while experimenting with the /give command i was unable to give the player a item that had attributes attached to it, the first photo was the item generated in 1.15 and the second item has been generated in the latest snapshot 20w22a

here is the line of text put into the command block generated by a website because its messy but quick.

/give @p stone{AttributeModifiers:[{AttributeName:generic.maxHealth,Amount:20,Operation:0,UUIDLeast:151462100,UUIDMost:99,Name:generic.maxHealth},{AttributeName:generic.maxHealth,Amount:20,Operation:0,UUIDLeast:151462200,UUIDMost:99,Name:generic.maxHealth}]} 1