4G/5G/4G&5G CA/5G ENDC?

At&t 4G, aka Hspa+, shut off in 2022. 

 4G/LTE is still running.  

You could have Googled this and gotten an answer.

https://www.phonearena.com/news/5G-bands-explained-Verizon-vs-AT-T-vs-Sprint-vs-T-Mobile-vs-World_id116781

And if you're using this information with the idea that you can select a phone or another device that will function on the network, don't, that's not how any of this works anymore. 

Manufacturers were required to submit devices to prove that they did work on the network in order to be included as acceptable devices. Any device that doesn't pass an IMEI check is excluded even if it has all compatible LTE bands.

https://www.att.com/buy/byod/identify?devicetype=phone

https://www.att.com/buy/byod/identify?devicetype=tablet