For infinite mana, ({3} magic symbol) ({R} magic symbol) ({R} magic symbol) is required, and your opponents must have at least 3 artifacts and/or enchantments.
For infinite creature tokens and mana, ({5} magic symbol) ({R} magic symbol) ({R} magic symbol) is required, and your opponents must have at least 4 artifacts and/or enchantments.
Steps
Cast
Dockside Extortionist for ({1} magic symbol) ({R} magic symbol) .
If you want infinite creature tokens, skip to step 8; otherwise, continue to step 3.
Dockside Extortionist ETBs, putting its ETB trigger onto the stack.
Tap
Lithoform Engine, copying the ETB and triggering
Kurkesh.
Pay ({R} magic symbol) for the
Kurkesh, copying the ETB an additional time.
Resolve both copied ETBs, generating at least 6 treasures.
Continue from step 11.
While
Dockside Extortionist is still on the stack, tap
Lithoform Engine for ({4} magic symbol) to copy
Dockside Extortionist, triggering
Kurkesh.
Pay ({R} magic symbol) for the
Kurkesh trigger, copying
Dockside Extortionist an additional time.
Resolve both
Dockside Extortionist copies, creating at least 8 treasure tokens.
Tap
Voltaic Key for 1 treasure token, untapping
Lithoform Engine and triggering
Kurkesh.
Spend 1 treasure token to pay for the trigger, copying the untap ability targeting
Voltaic Key.
Repeat for infinite treasure tokens, and creature tokens if applicable.