To unlock Lobo you are required to have access to Apokolips.
You can gain access to there once you have completed the main story mission from on top of Lex Corps.
You can return to earth near Granny’s Orphanage.
Once you are in you are required to complete all of the character quests, once you have done these you will then unlock the Lobo quest
Attack the goons on the way to the Throne room then take 3 selfies with him to unlock him.
Once you have unlocked Lobo
you can purchase him for 150,000 studs.
As soon as he is purchased pop achievement unlocked 50g richer.