Issue while deploying Custom FreshService App

Hello Team,

When I try to add a custom app in Freshworks Developers I get an error that says

“Sorry! We accept app manifest with Node.js runtime 12 only”.
When I initially downloaded the app code , the versions of node and fdk were :
“node” : “12.16.1”,
“fdk” : “6.13.2”,
I had to add some logs in the code for further debugging the issue , So when I tried to run the app using fdk run command , the app said the versions had to be updated in the manifest to the current node , when I did that and finally packed the app for updating in developer portal , I encountered the error i.e., “Sorry! We accept app manifest with Node.js runtime 12 only”.

PS : Tried the combination of node version 12 and fdk version 7 , still not helpful.