I have created an app link to sharepoint list. Under Title colum, it contain numbers and alphabets + number as per below.
On my Powerapps screen, searchbox, let's call it textsearchbox1. i want it to show error message in red color if user key in any number that is not in the SharePoint list. For example, in my sharepoint list Title column it contain number 78,79,IT01 and AJ0001. If user key in BA on textsearchbox1, a red error message will show.