Plugins Transfer Deactivaction-Reactivation

Greetings. I have purchased several plugins. I have to change the computer and deactivated them and then reactivated on the other one.
They have been purchased on Extension Warehouse (I do not think I have done it on Sketchucation Plugin Store).

I CANNOT find the way to deactivated them. Should uninstalling them from Extension Manager deactivated them on the old computer and make possible to activate them on the new one?
Thank you in advance for prompt response.

Yes, uninstalling them in Extension Manager should free up that activation. You would want to make sure to be signed in with your usual Extension Warehouse email address, though I imagine it would still work if you were on a different email address.

Didn’t realize this when I upgraded from 2018 to 2019 so it became real fun when I upgraded from 2019 to 2020. The support Peeps have been greatly helpful in getting this straitened out.
But, I have learned my lesson - Deactivate, uninstall, then upgrade to new version!