How come during calls no can hear me unless I put it on speaker mode?

Hi Dan,

Generally when we see this sort of issue, it's because one of the microphones built into the phone has failed; in this case it's the one at the bottom of the phone that's used when you make a phone call. By putting the phone in speakerphone mode, you're transferring the microphone input to the one at the top of the phone near the earpiece speaker.

Samsung suggests the first thing to do is, of course, to reboot the phone to make sure it's not a glitch. If that doesn't do the trick, they say you should try it in Safe Mode to make sure it isn't a bad app causing the problem. Here are their instructions for putting the phone in safe mode.

Try using the microphone in safe mode. If there is no problem in Safe Mode, it may be a problem caused by an installed third-party app on your phone. To find which app is causing the issue, you can try uninstalling the apps in the order of the last installation.

Step 1. Open Quick settings. Tap the Power icon at the top of the screen.

Step 2. Touch and hold Power off until the Safe mode icon is displayed.

Step 3. Tap Safe mode. If you've entered Safe mode successfully, you will see Safe mode displayed at the bottom of the screen.

I've had trouble locating repair guides specifically for your particular phone, but Step 19 of the screen replacement guide here on iFixit shows the part that holds the lower microphone. If the problem is indeed a bad microphone, then replacing that part should get you going again.

Samsung Galaxy A32 5G Screen Replacement - iFixit Repair Guide