Replacing rear solid axle with skewer
Leave the wheel in tact and see if you can order some 'turbo trainer axle nuts', pictured below, to replace your current nuts on existing axle. If these don't work for you then start disassembling the wheel but research first; you need skinny spanners called cone spanners (£?) to do the job properly and risk dropping ball bearings (annoying). Not normally a huge problem but if bike shops are closed and we're all social distancing atm, then you want to reduce the risk of messing up, temporarily, in case you are left without a functioning bike or help to fix.

Trying to patiently find a solution with low risk atm is reasonable.