Automation: When column is X, then Set Text to X

Hi, I’m to create the following Monday automation:
When an item’s text1 field changes to X,
Then set text column in the subitems to X.

The subitem columns are there, which is great. I see an action to set dates and numbers, but I don’t see an action to set text. Any reason why this is missing?

Can you think of a solution? Thanks in advance!