How can I grow / propagate villagers in Minecraft?

I'm already trying all the time to increase the number of villagers that I have healed.

I can't do it though. They don't take the food and nothing happens.
I don't know what to do next, I've also made enough beds…

Are the villagers not allowed to have a job, may I not have traded with them?
What are the conditions for the villager to multiply?

So as far as I know you have to put more beds than there are Villager. To do this, you have to throw them bread or carrots over and over again.

I've done all of that, but they just look at the food and don't give up

Do it / gamerule mobGriefing true

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