Thunderbird cannot decrypt emails forwarded PGP encrypted, because recipient does not match with the one in the key.
https://support.mozilla.org/en-US/kb/openpgp-recipient-alias-configuration
I found this article which didn’t work. Is there other way?
I’m not sure I am understanding your question…
It sounds like you have already added you public PGP key to your SimpleLogin mailbox, as described here:
https://simplelogin.io/docs/mailbox/pgp-encryption/
If so, to decrypt forwarded emails from SimpleLogin in Thunderbird you have to set-up Thunderbird with your private key. See here:
https://support.mozilla.org/en-US/kb/openpgp-thunderbird-howto-and-faq#w_i-have-never-used-openpgp-with-thunderbird-before-how-do-i-setup-openpgp
Does this help?