Raise them one at a time, then move to the next one. I like to put the jack under the U-bolt rather than on the tube. If you are trying to raise both wheels at the same time, then for sure you need to jack it up by the frame. Better if you have two jacks and some blocks.
Scotty and Kristen, Airedales Dagny and Wyatt
2007 Newmar Mountain Aire 4528, 450 HP ISM, Allison 4000, 8 Trojan T-105's
2019 F250 King Ranch 4x4 Powerstroke
Roadmaster Blackhawk 2, M&G 2.0 Proportional Brake System