A couple of thoughts:
1. Practice interjecting, and if other people are talking over your interjection, just keep talking until everyone shuts it. It will feel uncomfortable for you, but it's an important skill to have.
2. Is there some kind of a leader in these meetings? As a PM, I was often facilitator of discussions, and I would make sure to engage the smart but quiet types. I'd always talk to them about it first so as not to make them uncomfortable, and we could decide on what's best - maybe they make eye contact when they want me to interrupt on their behalf and ask their opinion, maybe I just ask them what they think at some point during each new topic we're discussing, or maybe they Slack me when they have something to say (this works well during Zoom/conf calls). Sometimes I talk to them for five minutes before the meeting to understand their general thoughts/questions about the topics at hand, so I know when to ask for their opinion. If there's anyone playing a formal or informal facilitator role, talk to them about this and work out a way they can make sure you're included.
3. If there's no facilitator but you're comfortable with some or all of the people in the room, talk to the people you're comfortable with at some point casually and mention that you find it tough to break into group discussions. There's a strong likelihood they don't even realize they're keeping you out of things, and when they do, they'll consciously try to include you. I come from a family of interrupters - none of us mean it rudely, and because we all do it equally at home, it's totally fine. When you put me in a room with non-interrupters, I make a very conscious effort to shut the hell up and let others talk even when I have something to say.
4. If none of these work, try communicating your thoughts outside of the meeting. If you have something important to contribute on a topic that's going to come up, just casually bring it up with other folks who are going to be there beforehand. Alternatively, send a follow-up email afterwards that opens with something like "Hey guys, I had a couple of thoughts I didn't get a chance to mention in the meeting because we ran out of time..."
But seriously, I do stress as someone whose natural instinct is to interject constantly that a lot of people who are like me either don't know it's a problem or do but have trouble controlling it. I'd never take offense if someone pulled me aside and pointed out that it's causing an issue.