That being said it’s a judgement call, if help is going to take a while to get there set yourself up in the safest manner and administer, if not reposition them on either their backs with their head tilted back or on their sides with an arm under their heads in case they vomit
Tbh I wouldn’t recommend giving narcan unless you are with multiple people, the best care for opioid od’s is rescue breaths, narcan just reverses the drug so they wake up. People can be extremely combative which can put you the patient and bystanders all in danger.
On top of them potentially being combative, they might also be on other drugs that won’t be blocked, for example they’re on meth and heroine and now you have someone jacked up on meth pissed at you for ruining their high.