Tauba After Committing Kufar
The only thing unforgivable is ‘istakbaar’ (ego/arrogance/hubris/rebellion against God), if one dies in that condition. For the rest of the sins, one has every chance to ask for Allah’s forgiveness and one should hope rehmat from Allah. Please also refer to the following video 39:57 to 44:14 https://youtu.be/UpP7IZXTdcY?t=2397