In Minecraft, how can I merge info from two map items while exploring?

Question

I've been exploring the end. I have a couple of full-scale (4/4) map items of the same region that have different parts explored. How can I combine the maps to make a single complete map?

For example, I have two maps of region A. On one map I have explored the WEST HALF of region A. On the other I have explored the EAST HALF of region A. How can I combine the two maps to have a COMPLETELY EXPLORED map?

Edit: Based on the first response below, here's a different way of saying it that may be more clear:

I don't want to merge two maps of DIFFERENT regions, I want to merge two maps of the SAME region. For example, let's say my friend and I start our maps in the same spot. He goes east, I go west. We come back to the center. Can we merge the info on those two maps of the same region to share the exploration info?

I tried putting the two maps into a crafting table (as how you would copy a map item to a blank map item) but with no success.

Note: almost all of the info I've found online is about merging custom world maps. That's not what I'm looking for; I want to merge two map items.

I'm playing Realms on PC (Java edition).

Answer 1

You can't merge maps. The only way to fully explore a map is to manually explore all the terrain shown on the map while holding that map. Once you do have the maps fully explored you can put them side by side in item frames and it will look like they are combined, but once you take them out they will just be singular maps.