How to find mushrooms in Minecraft

I am trying to make the regeneration suspicious stew. I can find the flower easily (I live in a plains biome), but the mushrooms are impossible to find. Where could I find them?

Solution 1:

You can find mushrooms in these areas:

1. Caves with less then twelve light levels
2. Sideways logs in forests sometimes
3. Swamps, giant tree taiga, mushroom biomes, and commonly in the Nether
4. Leaves of trees occasionally

I found this information from here.

Solution 2:

It's faster getting mushrooms by heading over to the nether or in caves. They seem to naturally grow in the world generation progress, and it makes sense why there are mushrooms in the nether (as of v.1.16).