I'm writing a story set in Bristol, UK (specifically the town of Avonmouth). So far everything has been geographically accurate, but if I want to make the story flow smoothly, I may have to replace parts of Bristol that do exist in the real world. My character has to go to an amusement arcade for... reasons, though to my knowledge, such a building doesn't exist in Avonmouth. I do not plan on publicly releasing the story, merely sharing it with a group of friends. It should be noted that this arcade will be a regular location the character visits.
Generally this is fine, but be consistent.
If you are generally meticulous about real life location and then, out of a sudden, start taking liberties with your writing, then some people who are very familiar with this location may not appreciate that.
On the other hand, if your writing is not very precise from the start, for example, you may very accurately describe some places, but be vague about the others, then people would get conditioned to some level of inaccuracy and let bigger liberties pass without notice.
Even if you are "inconsistent", it is perfectly fine to create fictitious establishments for plot reasons. If you have a 99.9% "Genuine city of Bristol" in your book, but the remaining 0.1% is a fictitious place where important part of your story takes place, this is Ok, and it happens in fiction all the time.
I mean, why not?
It easy to get carried away by the story and if a geographical feature disrupts your storyline, replace it with your own. For example, in Cassandra Clare's book (City of Glass) "Idris is located in Central Europe, between Germany, France, and Switzerland. Because of the wardings placed around the country and all of its borders, mundanes who come close to crossing it are instantly transported through to the other side of the barrier."
Another example is the underground tunnels that doesn't exist but still written beneath existent cities.
It fine to add a nonrealistic place into a realistic place if you have a use for it in your story.
Hope this helps!