How to set a date base in another custom field?

[Bridge2Lisbon Lda]

Hi! I'm trying to set up a date in a custom field based on another field.

I found this Arithmetic and formatting in date variables | Trello | Atlassian Support which looks like it is what I need but when I create a rule there is no blank space where I can simply put the variable. It only shows this:

How can I do to add the variable based on the other custom field?

[Sayed Bares _ServiceRocket_ · Accepted solution]

@Bridge2Lisbon Lda you can use set custom field action instead of set date custom field and then add your variable, here is an example:

[Bridge2Lisbon Lda]

Thank you! It worked :D