Solved Deprecated: Creation of dynamic property Kunena\Forum\Libraries\Config\...

Almost perfect.
Since I didn't have a backup, what I did was change all versions from 6.4.5 to 6.3.10 in the database extensions table and delete the record for version 6.4.5 in the kunena_versions table, without changing the update site URL. If I change it to version 3.6, it won't have the update to 6.4.x. Then, using the Joomla updater, I performed the update and then went to the Dashboard as Pikeltje recommended. All the updates were performed, and almost everything was fixed, with the exception of:
Deprecated: Creation of dynamic property Kunena\Forum\Libraries\User\KunenaUser::$twitter

And when I check the users table, it still has the "twitter" column. Instead, the "socials" column contains "x" (previously "twitter"). Therefore, I think the "twitter" column should also be removed from the users table in the next version.

Thank you.

Hello,

The twitter was renammed into x_social when updating to K6.3.3, i will add something in the update process of K6.4.6 to check all columns in table kunena_users and clean the ones which no need to be here.

Thanks, xillibit.
In version 6.3, there was an option to disable social media, which was in Settings >> Users. Now it's gone, and I can't find where to disable it. Is it possible to disable it?
Thanks.

It works with a template override.
Template Overrides | Kunena Docs
I removed lines 213–215 in .../site/template/aurelia/layouts/user/item/summary/default.php
and lines 131–145 in .../site/template/aurelia/layouts/user/edit/profile/default.php.
Unzip this uploaded zip file and copy the folder to .../yourJoomlaTemplatefolder/html