>>148959425
There are countless versions of immortality - there are fantasy/fairy tale versions, there are religious versions, there are science fiction versions, there are theoretical versions of quantum physics and complex mathematical theories abaut immortality.

Each of these options has its own nuances.
You can choose any that suits you, but each of these options for immortality requires certain knowledge and philosophy from you, and some even a little faith...

Please do not include time travel in the discussion of immortality, it adds unnecessary complexity.