If you have Botox for bladder spasms, you will probably (almost certainly) be unable to pass urine naturally. So what most people do is intermittent self catheterisation (ISC). Some can’t manage this so they would end up having a supra pubic catheter (SPC). You’d definitely be draining your bladder through some form of catheter.
But before you go straight for Botox, have you tried the various drugs for bladder spasms? Betmiga, or Tolterodine for example? The most common drug is Oxybutinin, but as it’s an anticholinegic drug, it crosses the blood brain barrier and can cause brain shrinkage. Something to be avoided I think!)
But you should get some advice from a bowel and bladder nurse, you can easily be referred, or even self refer.