They are published on the AOL website. To be clear they are not "for Thunderbird" email providers simply publish the settings you need to use to access their mail servers using mail protocols. They are the same regardless of the mail client. Excluding android style Apps which are glorified webpages and often use the same protocols as webmail. See https://help.aol.com/articles/how-do-i-use-other-email-applications-to-send-and-receive-my-aol-mail

The correct settings are:

imap.aol.com, 993, SSL/TLS, OAuth2, email address

smtp.aol.com, 465, SSL/TLS, OAuth2, email address

Check the authentication method (OAuth2) and that the AOL account is sending on the smtp with a matching User Name, not another or 'Default' smtp.

I have found incoming server imap but where is smtp settings. Thanks for help Im afraid Im bit dumb.

1. click 'account settings'
2. highlight the account in left side bar
3. in lower right side is a button 'edit SMTP server'

outgoing server settings Protocol Hostname

 SMTP                                         smtp.aol.com

Port Connection security 465 SSL/TLS

Authentication method Username

         OAuth2                                  mijso@aol.com

still wont send