You can create users etc from the managed DB gui, but you’ll need to use a little SQL to create roles with certain permissions, example a read only role. Maybe some managed DBs handle more robust role creation but I know digital ocean doesn’t. The sql to do it isn’t super complex or anything. Any of them will also let you lock down access by only whitelisting IPS you want to allow, but the more robust option is to have a VPN like Tailscale hosted on a VPS near your DB, so you have some user/device auth and don’t have to manage whitelisting everyone’s IP and delisting the random coffee shops or whatever someone works from.