The “Marketplace build number” for Confluence 7.14.0 is listed as 16524 in this document: https://developer.atlassian.com/server/confluence/confluence-build-information/
When I used that in an MPAC REST API I got an error response that said that was an invalid build number. I then reverse-engineered it by inspecting the HTML source on MPAC to see what the value was for the “7.14.0” option in the selector used to manually set the min build number.
The dropdown on MPAC has 16336 as the build number for 7.14.0.
I used 16336 and made it past the previous error so I’m pretty sure it’s a documentation bug.
I think that this is a high priority to fix in that doc because 7.14.0 is currently the oldest non-EOL version of Confluence so anyone who is using the MPAC REST API for publishing Confluence plugins is susceptible to running into the same trouble I did if they want to specify the oldest non-EOL Confluence version as the min supported version number.