Marking a field conditionally required

Hi,

I am working on configuring a section on my Account page.

Here I have a text field which is to be made conditionally required based on the input received in a picklist field.

So when Picklist field = Yes, my TextField should be required

and when Picklist field = No, my TextField should not be required.

On the TextField level, I set it as conditionally required and was trying to utilize the LookupValue function. But I am not sure of the syntax. Also the Syntax guide and Function examples do not talk about this function in particular. Could you please assist me with this?