As a DM, there are two reasons I ask this kind of question.

If it's a player that I know is comfortable playing their role, then I am trying to get them to lean into the scene to assist with story pacing, or potentially to reveal additional information.

There are still benefits to asking it though, even if a player is not comfortable playing out the scene. Even without a spotlighted stage, you can still obtain a lot of character development by asking for additional clarity. For instance, did the character want to use a cheesy pickup line, or maybe a humorous anecdote, maybe they want to be really suave.

I would probably ask some leading questions like the above, but that additional info can still greatly expand the scene without turning it into a night at the improv.

I usually rock a barbarian so i just shout or glower for charisma.

But if you’re honestly struggling then i’ll recommend something i used to do to gain confidence. Pretend to be someone else. Like when Abed pretends to be Don Draper. If you act as someone suave then eventually it won’t be an act.

The one caveat is be careful who you’re emulating. Don Draper is smooth but he’s also a giant misogynist. Unless that’s the character you’re playing as, then go nuts.

I usually ask for elaboration as a social puzzle for what my party picked up about bonds/traits/flaws (tbf they don't hit on random barkeeps). If they correctly target something they don't have to roll. If they lead with "let's ditch the twerp and take a spin around the sheets" to the NPC who tearfully asked them to help her protect her little brother that's going to be a roll to maintain relations lol. Or my party's fav for trying to join factions: "so you've seen me backstab my good friends, I'm in fact well and widely known for backstabbing, but I would never do that to you, I'm 100% devoted to the cause and also here's my extensive list of things I want for allowing you to license my name in your faction with a clause I reserve the right to refuse any duties I don't feel help me personally even though you're a noble order of paladins dedicated to helping the unfortunate for no reward" lmao (actual negotiation).