Have you done a search for this issue? The major issue with dongles is fake dongles, and is well discussed in the forum.
If you bought your dongle through ebay, than that is probably the issue, and has about 300 posts on the topic in this forum.
If you bought it through a reputable reseller, than reach out to Blackmagic support. This is more of a user forum, although Blackmagic will chime in every now and again.
You have most likely download the free Resolve and not the Resolve Studio. You would not be able to get into Resolve Studio after start up, as the Studio requires you to have a key or dongle to even properly launch.
Grew up with a Nikon FM Resolve & Fusion Studio 19 MBP M1 16GB/1TB MM M1 16GB/512GB TB4 1TB & 2TB MM i7 16GB/1TB & PowerColor Vega 56 8GB