The short answer: three built-in routes — paid memberships, paywalled content, and your own advertising — and you keep all of the revenue from every one of them.
Paid memberships. The most reliable model for most communities. Charge monthly for access, or run a free tier alongside a paid one. Free-plus-paid usually beats paid-only: the free tier keeps the network alive and populated, and the paid tier converts the people who are already getting value.
Paywalled content. Sell individual pieces — courses, reports, recordings, templates — without forcing a subscription. Works well for communities where the audience is broad but only some members want the deep material.
Your own ad network. Sell placements directly to sponsors who want to reach your specific audience. A niche community of 3,000 professionals is often worth more per impression to the right advertiser than a general audience ten times its size, and you set the price rather than accepting an algorithm's rate.
A realistic sequence. Don't monetize on day one. Build to a few hundred genuinely active members first, find out what they keep asking for, then charge for that. Communities that launch with a paywall usually launch to an empty room.
Pricing guidance. Look at what your members already pay for adjacent things — an industry newsletter, a conference ticket, a trade association fee. Price against that, not against consumer app subscriptions.
What to watch out for. Recurring revenue creates a recurring obligation. If your paid tier promises weekly content, you're now on a weekly deadline indefinitely. Promise what you can sustain on your worst month.
Tax, invoicing and consumer-protection rules for paid memberships depend on your jurisdiction. That's a question for your own advisor.