Start with the legal entity, not the brand
A brand name is not a licence. Find the legal entity name in the website footer or terms of business, together with a licence number and the name of the regulator. If any of the three is missing, that is your first answer.
Go to the regulator, not to the broker
Every credible regulator publishes a public register. Search for the regulator's own website, not a link the broker gives you, and search the register for the entity name and licence number. Check three things: that it exists, that the licence category covers what the broker actually offers, and that it is current.
Match the entity to the one you are contracting with
Large brokers hold several licences in several places. The question is which entity your account is opened with, because that determines which regulator protects you. This is in the client agreement. If the well-regulated entity is not the one on your agreement, the well-regulated licence does not apply to you.
Check how client money is held
Look for a plain statement about segregated client accounts held with regulated institutions. Vague language here ("secure", "protected") without the word "segregated" is a yellow flag.
Send one real question
Before depositing anything, ask support something specific about withdrawals. Who answers, how quickly and whether they actually answer the question tells you most of what a licence cannot.
What this looks like for Arabian Markets
Entity: Arabian Markets Ltd. Regulator: Financial Services Commission, Mauritius. Licence: Investment Dealer (Full Service Dealer, excluding Underwriting), number GB26206439. The FSC register is public; the steps above take about two minutes on it.

