Hello forum 

I installed odoo on the Ubuntu server and I am able to install third-party modules using this video https://www.youtube.com/watch?v=sRe1t4J8zA8&t=424s for community edition

Then I upgraded the community edition to enterprise using this https://www.odoo.com/documentation/16.0/administration/maintain/enterprise.html command for Linux 

After that I deleted the instance that I upgraded from community to enterprise then I couldn't find the third-party modules in the app list even after I updated the app list in other instances.