The sugestión was to check only for a part of the phone number. Let's assume, the phone number is +1 727-1234-5668, then you coukd use the contains block like this
If contains number
5678
Then...
To do it correctly let me suggest to remove all special characters from the phone number sbd check for only the numbers, i.e.172712345678
Use the replace all block several times to do this and use Do it for debugging
Use the companion app and Do it to debug your blocks, see also tip 4 here App Inventor: How to Learn | Pura Vida Apps
see also Live Development, Testing, and Debugging Tools
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