Not sure whether it’s the same in all authorities, but in ours we have to refer to BSCIP first, which is Bolton Social Communication & Interaction Panel. They often make a decision about ASD without it going to ADOS, but if undecided pass on to ADOS. We access BSCIP through our local CAMHS. If this is not the case for you, I would talk to the local SALT team, local SEND outreach team or paediatrics. We also have a local authority ‘Autism Pathway’, which is a document that signposts a route to take for assessment. I’ll attach a copy for you.
Have a good day!