Hi @hugor23000132 and welcome to the Adobe Community Forums.
These are user-to-user forums—expert users volunteer their time to help others use Adobe applications. We can explain features and policies but we have no more power to grand licensing exceptions or fix bugs than any other user.
Adobe's policy is to make N (the current version, which is InDesign CC 2026 v21) and N-1 (the previous version, which is InDesign CC 2025 v20) available via the Creative Cloud desktop app. If you want an earlier version, you will need to make the request with Adobe directly, but do understand that it is rarely made available. We can't help you here.
I recommend reaching out to your plug-in developer for help.
~Barb