I did this online the other week. After finally finding what I needed I tried to order and got that bullshit.

After trying to buy about £4000 worth of stuff I then find I can’t checkout as a guest and need to download an app and sign up.
I email to ask if I can just buy it as a guess and get a “Yeah, sure, just email with a list and we’ll invoice you” type reply.
I’m about to do it when I realise I’m the one jumping through hoops here, and it’s all bullshit. If they can do the guest thing through email then should give you the option on the website.

I order it from a competitor. It’s a bit more expensive, but only slightly. And no hoops or bullshit to contend with.