Cannot add keys

[jepessen]

Hi.
I've just installed the plugin on a 4.0.6.stable version on Ubuntu 20.04.
I was able to install the plugin, and I've tables on the database.
When I try to add my public key redmine tells me that there's an error

Error importing the key (please try again or contact your administrator)

Nothing more. The key is valid and in the log I don't find any error

I've installed gpgv1 from apt repositories and then in /usr/bin I've a symlink gpg2 -> /usr/bin/gpgv1

What should I do in order to add keys?

Just in case, what should I do in order to add manually keys into the database? I can perform a script to populate your table with correct data (it's better for me since we have many users and I don't believe that everyone will update their public key) If I know what should be inserted in every column.