Hi @bobj69 and welcome to the forum. That's a good question, because you can't rely on RM verification. You seem pretty polite so probably already have the answer to your question about broaching the subject. Just ask them politely using neutral terms. For example: "I'm interested in meeting, but for first-time meetings usually ask for a quick Facetime or recent photo with a date stamp. Does that sound OK?"
If that question offends a provider or they seem sketchy, I would pass. However, some escorts are discreet and genuinely concerned about sending face pics to strangers. In that case, you'll have make a judgement call - and make sure to meet first in a public place where you can walk away if he doesn't match his profile.