@Florin_Trifu, just to provide some context, the error you’re getting is due to the mongosh shell using a version of the Node.js driver >= 4.2.0, which only support MongoDB 3.6+ (per NODE-3469).
Though MongoDB 3.4 reached EOL in January, 2020 if you need to interact with a cluster on this version you can use the legacy mongo shell instead of mongosh. The legacy shell is bundled with either the Enterprise or Community server, but no installation/configuration is required (just extract the mongo binary from the archive file).