Hi @Grahambo05,
So here you would like to change a label control after button pressed?
we could add the following code after the formula of the Button onselect property:
UpdateContext({SubmitStatus:"Completed"})
Then change the text property of the label control with:
SubmitStatus
Besides, under the OnVisible property of the screen, add the following:
UpdateContext({SubmitStatus:""})
Besides, DataCardValue should be bound with the corresponding field of the data source, if you would like to change the value within the App, then there are more details that you need to take notice of.
Check the article below for reference:
Understand data forms in Microsoft PowerApps
Regards,
Michael