How to trigger mural/guardian offering?

[elfin sail]

I've reached town rank A for a few days already (I think it's been a week if I'm not wrong), already got town attraction, song of the sea, savannah, and reach town rank S mission, but I still havent gotten the mural/guardian offering quest.

I went to the lake a few times but nothing. Is there anything I should do to unlock them? Thank you in advance

[bright berry]

If you've already seen the town rank celebration, go to the goddess lake. Don't warp there, just run there.