Hello:
Today I faced the same situation where I needed to be able to access my desktop environment (MATE) clipboard, just as I do in another laptop with different OS.
TL;DR: you need a different package instead of the vanilla vim-8.2.4851. In my case, it was vim-gtk3-8.2.4851. Use pkg search vim in order to see which one is appriate for your desktop environment.
Details:
Normally, from inside vim I can select something and press "+y in order to have it copied into the DE's clipboard. Then, I can go to any other app (E.g. Pluma) and use Ctrl+v.
It also works the other way around, I copy something from any app in the desktop environment (Ctrl+c), then I can paste it in vim using "+gp, which will have a similar effect as Ctrl+v, but will avoid undesired indentation and new lines to be inserted if you are copying code between apps.
Initially I had installed vim-8.2.4851 using pkg. This resulted in -xterm_clipboard. After installing vim-gtk3-8.2.4851 (which automatically removed vim-8.2.4851), I have +xterm_clipboard enabled.
I hope this helps.