They still have the AGL contract but AGL wasn't taking much gas...

They still have the AGL contract but AGL wasn't taking much gas out of it when it rolled over on January 1 2020, there was an immediate, large drop in CTP's production. I don't know what's happened since then but I doubt they're drawing much, plus CTP's ability to deliver gas has taken as a hit due to natural field decline, which is why they need this new drilling program.

What is stopping AGL from taking all CTP's gas is the cost of shipping it to Melbourne and Sydney where it's most needed. It has to go through at least 5 major pipelines to reach Sydney and the tolls are simply too much, especially given the recent depressed gas prices as a result of COVID. Richard Cottee as CTP's MD tried to get regulatory changes to make it cheaper to supply gas to the east coast from CTP's fields but had limited success.

This is why CTP is now pushing the Amadeus-Moomba pipeline. Even if it's the same cost per GJ as the NGP it will still be much cheaper to reach Moomba as they won't have to pay the tariff on the ADP, CGP and SWQP. From Moomba the price is cheap as the Moomba to Sydney pipeline is dirt cheap.

I notice the NGP tariff is now up to $2.33/GJ with nitrogen removal, due to CPI adjustments. Add in around $1.50/GJ in CTP's opex plus about another $2.50 in other pipeline tolls. The Wallumbilla spot price is only hovering around $6/GJ presently so that is the major impediment to CTP selling more gas to the east coast.