I had a bike mishap and broke the Tourney SL-TX50-7R shifter.
I am having a tough time finding one. No one has stock and they are pricey.
Can I use any Shimano 7 speed like a SL-TX30-7R as a replacement or does the shifter have to match the Tourney rear derailleur?

You can use (basically) any 7 speed shifter for the rear. Front shifters can have some variance in indexing (that usually is workable anyway), also, most of those low end systems have friction front shifting anyway, or micro ratcheting, like your old ones, so they'll work with anything.

I bought some of those TX50 shifters off aliexpress a while ago, seem pretty good.
The other option is you could just set it up with a friction shifter. Most co-ops would have friction stem shifters for very cheap or free.

Another option: a Chinese vendor on eBay is offering a new TX50 shifter set, 7-speed, for about $20US - including shipping to Canada postal code K0J 1H0, if I did the check correctly. Don't know what Canadian customs and other taxes will add to that.

https://www.ebay.com/itm/363896939418

Delivery could take a while, though. And as always when buying from, ah, selected sources and locations: caveat emptor.

Any 7 speed shimano compatible shifter. Look at Microshift as well

https://cambriabike.com/products/shi...AaAveyEALw_wcB

https://www.ebay.com/itm/28429465401...1&isGTR=1#shId

​​​​​​https://www.amazon.ca/microSHIFT-Shi.../dp/B01415SL8W

​​​​​​https://www.mikesbikeshop.ca/product...r-377415-1.htm

Thanks guys. I was pretty sure I could use any Shimano 7 speed shifter.

Just one more question.
If I remove the existing cable from the outer cable to install a new shifter which usually comes with a cable I'm worried about fishing a new cable in since most of the outer cable is in the frame.
Is this something I should worry about?
Can I remove the cable from the shifter end of the old shifter and replace the cable on the new shifter without removing the cable from the outer cable?

Just FYI it is not good to post the same thread in different sub forums.

Yes. However cable housing is very cheap and this is a good time to replace it. At the least, inspect both ends of the housing for wear, and test a cable through it to see how much friction it has. Running housing through a frame like that is usually easy as you just push it through, there's a tube in the frame it runs through. And you can just copy the size of the old one. Getting good cuts on the housing is the only hard part.

Sorry I misread you. No you cannot. You have to remove the inner cable. You can leave the outer in place. Often, the inner cable will be frayed where it clamped, and impossible to re-insert, so you will probably want a new inner cable.
Many shifters come with cables.

Your right. Sorry!