Most these attachments connect to the toilet's water supply, which is fine, except most toilet water supplies only provide cold (i.e. whatever the ambient water temperature happens to be) water which to me, is far from ideal in a bidet (it's fine for normal use though).
Running hot water there is a significant undertaking if done correctly, so most options come with a small reservoir to heat up water from the regular toilet supply.
That heat isn't magical, it needs energy from somewhere meaning you need to run power there someway.
There are dangerous improvised solutions like running a power cable yourself. There's additional consideration electricians put in when installing power in restrooms due to all the water and grounding dangers from metal plumbing. Running cables neglects all that thought and reintroduces an electrocution hazard if not handled very carefully.
That leaves me with battery options which I haven't looked to much into but I find that's likely not ideal to swap batteries around all the time. If it can operate off something like a deep cycle marine battery (which seems appropriate), then it might be viable.