dynamics 365 syntax for if contains data

[Imrannaqvi]

I am building a flow that I want to trigger when a field in D365 is updated or contains data. 

Example wait until contact field contains data. I can't seem to find an option for this.

[v-yamao-msft]

Hi Imrannaqvi,

For your scenario, you may consider using the trigger “When a record is updated”, then adding a Condition to check if the specific field contains data.

In the Condition, in advanced mode, configure the function with empty function.

The function might be configured likes below:
@empty(triggerBody()?['VSTF_x0020_ID'])

After the condition, adding actions under if yes or if no branch according to your needs.

Please check more details about empty function at here:
https://docs.microsoft.com/en-us/azure/logic-apps/logic-apps-workflow-definition-language

Please try it on your side. If you need more help, please feel free reply.

Best regards,
Mabel Mao