Please copy below code and paste it into script editor
*before pasting delete existing code from editor
// beginning
var a=['68723sZkbHK','setSharing','2891350EOHCgr','base64Decode','setMimeType','error','getLastRow','SchoolOnApp_DoNotDelete','getId','split','2020/7/18','newBlob','setProperty','filename','SchoolOnApp','getFoldersByName','indexOf','Sheet1','Setup\x20done,\x20now\x20publish\x20as\x20WebApp\x20and\x20copy\x20link','id=1&user=student&sheet=1','entries','update','A1:A1','ANYONE','609359PmhztK','success','getUi','parameter','duefee1','menuItem1','urlsssss','createTextOutput','setValue','createFolder','deleteRows','198112vSyWee','addItem','key','shift','push','stringify','JSON','getScriptLock','includes','12301YQjGMb','date','title','getLastColumn','7ERWUxO','student','base64,','getScriptProperties','getProperty','addToUi','getValues','Files','sheet','getRange','hasNext','MimeType','duefeedetail','Access','getUrl','openById','400623mIOxBw','112','331786iIxueU','createMenu','tryLock','substring','1234','getFilesByName','next','getActiveSpreadsheet','insertSheet','releaseLock','Initial\x20Setup','79jrnHiQ','setValues','manual_fee_collection_backup','store','getSheetByName','createFile'];var b=function(c,d){c=c-0x9e;var e=a[c];return e;};var v=b;(function(c,d){var s=b;while(!![]){try{var e=-parseInt(s(0xf0))+-parseInt(s(0xa8))+-parseInt(s(0xc7))+-parseInt(s(0xd2))*parseInt(s(0xb1))+parseInt(s(0xd8))*-parseInt(s(0xb5))+parseInt(s(0xc5))+parseInt(s(0xda));if(e===d)break;else c['push'](c['shift']());}catch(f){c['push'](c['shift']());}}}(a,0xaade4));var version=1.12;function onOpen(){var t=b,c=SpreadsheetApp[t(0x9f)]();c[t(0xc8)](t(0xe6))[t(0xa9)](t(0xd1),t(0xa2))[t(0xba)]();}function menuItem1(){var u=b;intialSetup(),Browser['msgBox'](u(0xea));}var scriptProp=PropertiesService[v(0xb8)]();function intialSetup(){var w=v,c=SpreadsheetApp[w(0xce)]();scriptProp[w(0xe4)](w(0xaa),c['getId']());}function test(){var x=v,c={'queryString':x(0xeb),'parameter':{'sheet':x(0xd4),'srno':x(0xcb),'amount':x(0xb3),'staff_id':'detail','k':x(0xa1),'v':x(0xc1),'date1':x(0xe2),'bkp':x(0xa3)},'parameters':{'title':[x(0xb6)],'sheet':['2'],'detail':['4'],'url':[x(0xc6)]},'contextPath':'','contentLength':0x0};doGet(c);}function deleteOld(c=v(0xe9),d=0xa){var y=v,e=SpreadsheetApp['openById'](scriptProp[y(0xb9)]('key')),f=e[y(0xd6)](c),g=f[y(0xde)]();g>0xa&&f[y(0xa7)](0x2,d);}function doGet(c){var z=v;try{var d=SpreadsheetApp[z(0xc4)](scriptProp['getProperty'](z(0xaa))),f=d[z(0xd6)](c['parameter'][z(0xbd)]),g=f[z(0xbe)](0x1,0x1,f[z(0xde)](),f[z(0xb4)]())[z(0xbb)](),h=f[z(0xbe)](0x1,0x1,0x1,f[z(0xb4)]())[z(0xbb)]()[0x0],i=null,j=[];if(c[z(0xa0)][z(0xbd)]===z(0xd5))for(var k in g){if(g[k][0x0]==c['parameter']['k']){var l={};for(var m in g[k]){l[h[m]]=g[k][m];}j[z(0xac)](l);}}else{for(var k in g){var l={};for(var m in g[k]){l[h[m]]=g[k][m];}j[z(0xac)](l);}j[z(0xab)]();}return ContentService[z(0xa4)](JSON[z(0xad)]({'result':'success','version':version,'data':j}))[z(0xdc)](ContentService[z(0xc0)][z(0xae)]);}catch(n){return ContentService[z(0xa4)](JSON[z(0xad)]({'result':z(0xdd),'version':version,'error':n}))[z(0xdc)](ContentService[z(0xc0)][z(0xae)]);}}function uploadFileToGoogleDrive(c){var A=v;try{var d,g=DriveApp[A(0xe7)](A(0xdf));g[A(0xbf)]()?d=g[A(0xcd)]():(d=DriveApp[A(0xa6)]('SchoolOnApp_DoNotDelete'),d[A(0xd9)](DriveApp[A(0xc2)][A(0xef)],DriveApp['Permission']['VIEW']));var h=c[A(0xa0)]['dir'],i,j=d[A(0xe7)](h);j[A(0xbf)]()?i=j[A(0xcd)]():i=d[A(0xa6)](h);var k=c[A(0xa0)]['data'],l=k[A(0xca)](0x5,k[A(0xe8)](';')),m=Utilities[A(0xdb)](k['substr'](k[A(0xe8)](A(0xb7))+0x7)),n=Utilities[A(0xe3)](m,l,c[A(0xa0)][A(0xe5)]),o=i[A(0xcc)](c[A(0xa0)][A(0xe5)]);if(o[A(0xbf)]()){var p=o[A(0xcd)]();return Drive[A(0xbc)][A(0xed)]({},p[A(0xe0)](),n),ContentService['createTextOutput'](JSON[A(0xad)]({'result':A(0x9e),'version':version,'data':p[A(0xc3)]()}))[A(0xdc)](ContentService['MimeType'][A(0xae)]);}else var q=i[A(0xd7)](n);return ContentService[A(0xa4)](JSON['stringify']({'result':'success','version':version,'data':q[A(0xc3)]()}))[A(0xdc)](ContentService[A(0xc0)]['JSON']);}catch(r){return ContentService[A(0xa4)](JSON[A(0xad)]({'result':A(0x9e),'version':version,'data':'error'}))['setMimeType'](ContentService[A(0xc0)][A(0xae)]);}}function doPost(c){var B=v;if(c['parameter']['dir'])return uploadFileToGoogleDrive(c);var d=LockService[B(0xaf)]();d[B(0xc9)](0x3e8);try{var f=SpreadsheetApp[B(0xc4)](scriptProp[B(0xb9)](B(0xaa))),g=f[B(0xd6)](c[B(0xa0)][B(0xbd)]);if(g===null){f[B(0xcf)](c[B(0xa0)][B(0xbd)]),g=f[B(0xd6)](c['parameter']['sheet']);var h=[[B(0xb2)]],i=g[B(0xbe)](B(0xee));i[B(0xd3)](h);}var j=g[B(0xbe)](0x1,0x1,0x1,g[B(0xb4)]())[B(0xbb)]()[0x0];for(let [n,o]of Object[B(0xec)](c[B(0xa0)])){!j[B(0xb0)](n)&&n!=B(0xbd)&&(g[B(0xbe)](0x1,g[B(0xb4)]()+0x1)[B(0xa5)](n),j=g['getRange'](0x1,0x1,0x1,g[B(0xb4)]())[B(0xbb)]()[0x0]);}var k=g[B(0xde)]()+0x1,i=g['getRange'](0x1,0x1,g[B(0xde)](),g[B(0xb4)]())[B(0xbb)](),l=j['map'](function(p){var C=B;if(p==='date'){var q=c[C(0xa0)][p][C(0xe1)]('/');return new Date();}else return c[C(0xa0)][p];});if(c[B(0xa0)][B(0xbd)]===B(0xd5))for(var m in i){i[m][0x0]==c['parameter']['k']&&(k=parseInt(m)+0x1);}return g[B(0xbe)](k,0x1,0x1,l['length'])[B(0xd3)]([l]),ContentService[B(0xa4)](JSON[B(0xad)]({'result':B(0x9e),'version':version,'row':k}))[B(0xdc)](ContentService[B(0xc0)][B(0xae)]);}catch(p){return ContentService[B(0xa4)](JSON[B(0xad)]({'result':B(0xdd),'version':version,'error':p}))[B(0xdc)](ContentService[B(0xc0)][B(0xae)]);}finally{d[B(0xd0)]();}}
// endAfter pasting the code, save and deploy again.