In electronic music it's very common for collaborating artists to release music as a duo, like "Sasha & John Digweed" or "Pig & Dan". But on music platforms like Beatport & Spotify, these kinds of names & collaborations have complicated rules.
When record labels want to release music by "Artist A & Artist B", the general requirement is that each artist profile is added to the song separately, as "Artist A" and then "Artist B". There are a few reasons why this is a rule:
It makes sure the collaboration is visible on both Artist A and Artist B's existing artist profiles.
It helps notify all the fans of Artist A & Artist B that they have a new release out. If it was released under one name, "Artist A & Artist B", then the fans of each profile would not get notified automatically.
It helps prevent duplicate profiles being created on music platforms, who don't want multiple profiles when searching for the same artist.
And at Proton, when you add multiple artists to the same track, you can easily control the order the names appear on all platforms except Beatport. (details here).
In industry terms, the combined artist profile "Artist A & Artist B" is called a Compound Artist -- because it's 2 different artists combined/compounded into 1 profile. Compound Artists are outlawed on all major music platforms like Spotify, Beatport, Apple, etc.
But... there are exceptions.
If members of the duo don't release music independently, and only release music together, then it's OK to use a compound artist in some cases, but only if both artists feel strongly about it and they have no plans to release music on their own names separately down the road.
Sometimes collaborations will choose shortened names, like "Pig & Dan", where the individual names "Pig" and "Dan" would otherwise be very hard to find on their own, and may also not release separately. In cases like this it's allowed.
In general, always add artists to your tracks separately without creating compound artists. If you have an exception, you can contact Proton Support (support@protonradio.com) and ask for help setting up the profile!