This modification adds three features:
1.Search portal

Throw the eye of the ender without moving, and when it stops moving, press your key bind.
Then move away about 50 meters and repeat. If everything worked, you should receive a message in the chat with the coordinates.
If unsuccessful, you will receive an error in the chat.
2.Converting coordinates from overworld to nether and vice versa

To convert, send a command using the following formula:

/CordsConvert "Dimension to which coordinates to convert/auto" "X" "Z" "auto is similar to ~ ~ but ignores custom coordinates"
Overworld
- converts overworld coordinates to nether coordinates
Nether
(New) 3. Finding a portal using 1 eye of ender

To start, stand at the point where you want to throw the Eye of Ender, throw it, and when it stops flying, press the key bind.
Note: I don't recommend using this because it can return both correct and incorrect coordinates within a 500 block radius (the largest radius in the three worlds I created for testing).
The average spread is ~300 blocks.

- converts nether coordinates to overworld coordinates
Auto
- Automatically takes the dimension you are in.

The mod is entirely client-side.
There may be some bugs.
I also don't recommend using the mod on servers with anti-cheats, as the mod isn't a cheat. However, to make it work with the automatic portal search, it will automatically point you toward the Eye of Ender, and the anti-cheats might think you're a cheater.

(Aps)Auto portal search