If you want a front fender mount, this one works on the new body style:
Amazon.com: Valley Enterprises Fender Mount Antenna Bracket 3/4" NMO Mount for 2019-2021 Dodge Ram 1500/3500 Driver's Side : Electronics
smile.amazon.com
Getting it through the firewall is a bit of a chore on the ED as there is not a lot of room where the built in hole is. After cutting the nipple I lubed the wire with Japanese knife oil and it went through fine, had to stop every now and then and back it out as the nipple started to collapse on itself.
Note that this pass through is not very big, so if you have a cable with connectors already you may need to cut one off.
Going to drill holes in the magazine rack on the drivers side console to mount my radio.