The end of Mojang accounts is approaching, so if you haven't migrated your Mojang account to a Microsoft account, you will want to do that.
You have until September 19, 2023, at 11:00 am EST/17:00 pm CEST to migrate your account, after which you will be unable to migrate your Mojang account via the vanilla launcher or Minecraft.net. Minecraft Support will also be unable to help you after that.
As a reminder, this is not something that Technic controls or can help you with. If you have issues logging into your Microsoft account in Technic Launcher after you migrated, please head over to #tech-help in our Discord server. (There's a quick self-help in the pinned messages if you don't feel like waiting)