I once heard a recommendation that there's nothing better for neurodivergent people then to spend time with their own. Have a look and see if any places near you do sensory/neurodivergent events. I am thinking of things like cinema screenings and soft play. As awareness seems to be growing in some countries demand is emerging for e.g. low volume cinema screenings, lights turned down, low numbers of attendees etc. Whilst your child might not need all these accommodations there will be other children there who are neurodivergent for them to meet and (hopefully) a higher level of acceptance and understanding amongst all the parents.

If your child has special interests then events focussed on those subjects may attract similar types of children. It's a bit of a cliche/stereotype but communities like boardgames, pokemon, videogames, train enthusiasts etc often have events/rules/customs that provide clear ways to engage with others even non-verbally. For example there are people running Minecraft servers purely for neurodivergent children.

If you're really lucky there may even be parent meet ups or workshops in your area that bring neurodivergent kids together and help them to value their difference. Creating a social life independent of school for your child could be really valuable in their years ahead and for you too, helping them keep a core group of friends even when they transition between schools.