Making a teleporter is easy. you need 4 things.

1 block of either obsidian, crying obsidian (bottom)

1 block of waxed copper

1 block of either quartz, amethyst or emerald (top block)

and a redstone wire on the very top

to active the portal power the redstone wire. A button on the side will do this nicely. The game checks ever 1.25 seconds to see if it needs to teleport (it checks the wires power at that time)

It will send all entities within 5 blocks to the FARTHEST portal with the same type. So quartz to quartz and amethyst to amethyst.and emerald to emerald. if you have more than 2 of 1 type, the farthest destination away from your current position gets selected. if you have 1... you don't really go anywhere.

You may have up to 6 teleporters. This is mainly due to a constraints of how minecraft works as each teleporter has a ticking area next to it to keep it active when a player isn't around.

When the teleporter comes online. It looks at the top and bottom block to understand what it sends and where it sends it to. Changing these after the teleporter is online has no effect. If the waxed copper block is destroyed the teleporter will go off line and no longer count as one of your 6 teleporters.

The teleporter can either send players items and mobs. or just players and items.

Obsidian - mobs, items, players

Crying obsidian - items, players

If a player doesn't want to be teleported they can carry a mundane potion in their hotbar on them and the teleporter will ignore them when it activates.

Because the teleporter activates via redstone signal you can setup all sorts of contraptions to activate it when you want (and not till then)

I also migrated this to java if you want that edition you can find it here https://www.curseforge.com/minecraft/customization/teleporters-je

Teleporters