The cord that connects the phone board to the screen is damaged?

This is, as far as phone repairs go, one of the easier repairs there are, so if you have just a couple of tools it's a job you should be able to do yourself without a problem.

There's a YouTube video that shows you pretty much exactly what you need to do to replace that flex cable; basically you just have to take off the rear battery cover of the phone, then remove the midframe and you're there. Unplug three connectors on the cable and you can pop a new one in.

Samsung Galaxy a30s

If you prefer step by step written directions, there's a screen replacement guide that has all the steps you need, but of course you'll have to judge for yourself what parts to do and what parts to ignore.

Manuales / Samsung Galaxy A30s / Fullscreen

I'd say you follow it through Step 4, but only do the first instruction on that step, that of unplugging the cable. From there, skip down to Step 7 and follow along the first three instructions on that step. That should get you there.

The part itself shouldn't be hard to find; here's one that came up on AliExpress after just a moment's worth of searching.

New Good Main Flex For Samsung Galaxy A30s A307 A307f Motherboard Main Board Connector Lcd Display Flex Cable Repair Spare Parts - Mobile Phone Flex Cables - AliExpress

Good luck; let us know how it all turns out!