That looks like a build, not buy.

Do you really want to climb down a ladder at 3 AM to have to pee?

You can probably buy the "elements" to do this, but will require a carpenter to assemble and painter to paint and some clever sewing to complete the look. Do you have the budget to accomplish that? I guess you are trying to max, storage with the loft sleeping. Are you young? Are your knees OK? Have you considered a Murphy Bed arrangement with some storage instead? Much more comfortable. Easier for that night time trip Jennifer referred to above as well. (good point Jennifer! )

Great idea. It needs to be built from scratch. The ladder looks like it might have been a purchased component from the lumber yard. Make the ground floor as short as you can be comfortable with, in order to maximize headspace on the loft. Mark out the platform on your wall in blue painters tape first, to make sure that you are comfortable with the dimensions before you start to build.

I would suggest before doing this you try out a loft bed with no headroom we had them in our cabin and when we were kids they were awesome but once we go taller they were really claustrophobic and almost impossible get out of and to be honest that one looks like if you weigh more than 100 lbs your butt would have a hard time getting into bed . A loft bed to really work needs to go into a space with at least 12-14 ft. ceilings

Try a Murphy or Panel Bed !

https://www.murphybedatlanta.com/