Hey Prima01960,
It sounds like you will try tapping a number to join a meeting, but nothing happens when you press it. To start, you can see if restarting your device may help. Restarting can seem like a simple step, but it can sometimes help resolve unexpected issues. If you have an iPhone, the steps below from the following article, show how to restart: Restart your iPhone - Apple Support
"How to restart your iPhone X, 11, 12, or 13
- Press and hold either volume button and the side button until the power-off slider appears.
- Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
- To turn your device back on, press and hold the side button (on the right side of your iPhone) until you see the Apple logo.
How to restart your iPhone SE (2nd or 3rd generation), 8, 7, or 6
- Press and hold the side button until the power-off slider appears.
- Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
- To turn your device back on, press and hold the side button until you see the Apple logo. "
You'll also want to make sure all apps with the issue are fully updated as well: How to manually update apps on your Apple device - Apple Support Having updated apps means you are running the latest version that is compatible with the iOS yours device is running, along with any possible bug or issue fixes as well.
Let us know how that goes.
Take care!