On the wiki it describe two different ways a populated village attempt to spawn iron golems.
The first way is by villagers either not detecting an iron golem or are panicking because they can see a hostile mob
The second (supposedly used by Bedrock) way is to have at least 20 beds and 10 villagers with profession.
To verify that I have satisfied the criteria for the second method I had constructed additional houses (with multiple beds in each) and a large house with 20 beds right next to the village center (the well, with the bell), as well as placing down 4 cauldrons, 2 of blast furnace, grinding wheel, stone cutter, brewing stand, loom, lectern, smithing table, fletching table and catography table. I also made sure there is a good amount of space around the center to allow golems to spawn.
To satisfy the first criteria, well, part of the first criteria is already met because there was never an iron golem in this village. But to satisfy the second part I trapped some zombies and trapped a villager right next to them (separated by a slab) along with a bed so he can always see the zombies. Not to mention the spiders and other hazards (e.g. skeleton horseman trap) that had naturally spawned
I let the game run for an hour. However, no golems are spawned.
Comments 3
No, this is still an issue because
the villagers have the ability to pathfind to their own sites, and there are more jobs than villagers
the villager will be randomly unable to pathfind to their own bed/site while able to do it in other times, which prevented the case of >=75% of the villagers to work in one day actually from checking true
this is under player's intervention to add more jobs, houses, beds and leveling terrain for villagers to access them easier
It's incredibly difficult to meet these requirements, except in creative mode on superflat
You do not describe any villagers actually working. 75% of the villagers in a village must have worked (accessed their linked workstation) during the past game-day. Also, the bell does not define the village center.
I recommend you read the wiki more carefully and search for a Bedrock Edition iron golem farm tutorial.