ᐅ Properly Aligning an Ikea Pax Wardrobe

Hello everyone – a question for the experts: how would you align a wardrobe?
Yesterday I assembled all my Pax units and roughly placed them in their spots. So, what’s next?
Should I first level them with a spirit level, then secure them to the wall, and only afterwards install the components (drawers, shelves, clothes rails, etc.), or should I install the components first, then level and fix the wardrobe?

Our installers leveled the cabinet before fitting the doors and shelves. They did not fix it to the wall, as agreed with us, since we do not have children who might use the cabinet for climbing.

After leveling with the adjustable feet, the side panels should be supported from beneath (especially if the cabinet is not attached to the wall), as otherwise the bottom panel of the PAX can easily break.