Sorry to sound like a parrot but having worked with video for twenty years or so, I would never use the onboard microphone on any camera for anything but record a track for synching. Not only will you pick up motor noise, be it from auto focus or internal fans or HDDs in video camera's, you will also pick up every little bit of noise from your fingers either operating the camera or adjusting your grip.
Personally, I wouldn't even use any microphone which is physically attached to the camera, even via a shock mount, if at all possible, if you intend to use the video for professional use. That said, I acknowledge that if you are working alone, it isn't practical to set up an external audio input and I have a RØDE mic which I have to use sometimes.
Even the cheapest microphones can be better than the built in microphones and whilst I accept that a balance has to be found between quality and budget, I have found that BOYA shotgun microphones are reasonably priced if you are have limited funds and quite acceptable if set up correctly, i.e. on a microphone stand and not mounted on the camera.
If you intend to pursue video production seriously, I would (as I have done) invest in a Zoom H6 and record audio entirely separately; remembering to set the sample rate to match the video you are shooting, usually 48kHz, but to get the best out of it, you would need an accomplice who knows what they are doing.
It is pretty simple to synch the audio in a video editor by showing audio waveforms on the time line, zooming in and matching peaks, but third party applications like Plural Eyes will automate the process for you. Don't forget to delete or mute the camera audio from your timeline before your final export.
Sorry for going on but so many videos are ruined by bad audio.
And as a total killjoy post script, I keep video and photography quite separate, I have HD camcorders to shoot video - I'd only use my D5500 if I was caught out and saw something worth recording when I was without a camcorder.