Why can't I find my friends' gamertag in minecraft?

I play Minecraft at switch and I already have a Microsoft account. Unfortunately it doesn't find my friends' gamertag, why?

Ps.:they said they somehow have minecraft java (I haven't had minecraft for so long)

Minecraft Java and Minecraft Bedrock edition (Microsoft) can't gamble with each other…

Minecraft on the Switch is the Bedrock edition. Although it is almost exactly the same as the Java edition, it is still not exactly the same. You can play with everyone who has the Bedrock edition, but not with the Java edition.

The Java edition is, so to speak, exclusive to the PC