You may want to use another term than bdsm slave, compare to a provider that does offer fetishes or pro-sub, a slave in the context of bdsm takes a lot of trusts, is normally a long term committed relationship, not just an hour or few with a providers.
There is Carmela Grande that is currently touring Ottawa till tomorrow (Saturday) I believe that does offer this service, except for that there is no one at the top of my head that does right now.
As some others members stated in previous comments, if you find someone, Id suggest off the bat that you do a duo with a friend of the provider, who either is more vanilla or act as a co-top with you. Its safer for the SP and more easy to be put in a submissive position.
And yes fetlife and when things get more back to normal, attend munches, play parties, get know to be someone that can be trust, that take workshops and the like . Im in bdsm in my personal life and did for a really really brief time offer pro sub and most men have absolutely no ideas what they are doing pass rough sex and hand spanking