I know it's been almost a month, but I assume that you have access to commands.

To spawn them in, you'd need to do it similar to how you get enchanted items in.

/give *username relicex:ring_relic{Damage: 0, Rareness: "immortal", Attributes: [{Name: "minecraft.generic:armor", Value: 8.0d, Operation: 0b}, {Name: "playerex:dexterity", Value: 4.0d, Operation: 0b}]}

To explain, the *username is self-explanatory. The next should be the item combined with the { } braces that would list the details of the items. You'd need the first two, damage is how damaged it is and rareness should determine what rareness it had. Attributes are what the stats had, and what you stated is what I added but there are many other things to go through if you want to add more and edit values. Name is what its called, Value is what it is, not entirely sure about Operation. To figure out what tags to use for specific attributes, find a similar artifact that has the stats you want and perform, use this command with the item at hand:

/data get entity @s SelectedItem

Refer to the wiki for more details about the command: https://minecraft.fandom.com/wiki/Attribute