How i can tests and install external shopware plugin from shopware shop on my local machine?

Shopware 5 International (English Only)
4

Did all that, but no matter what I do I only get:

First:

Error The requested plugin has already been purchased. Error code: PluginLicensesException-4

Then when I tried to go to plugins:

Error Unknown error occurred. (UserShopsException-20) Error code: UserShopsException-20

There nothing more in error log.

Then I turned to the Shopware Account - where I have to verify domain assigned to the account. So I have to buy and verify a domain just to download free plugin?