Condition on behavior

[ATR]

I’m trying to create an action that is only avaible when a row from a child table is not empty. My parent table is “NotasData” and it’s child table “CobrançaData”. So when the row “Valor Pagamento” is empty the user should not be able to do the action. I used this formula bellow and it didn’t work:

ISNOTBLANK([Related CobrançaDatas].[Valor Pagamento])