The landlord have the authority to pick what he wants to all in or off the lease . That's way it's your responsibility to read ing go over the lease in the present of the landlord. So you can know what to expect when you sign it. But yes if you want heat get gas.
You will need to be responsible for all issues regarding the gas if it is not covered in your rent and listed on the lease. You can ask if there is a deposit required with the gas company. Some do not require one.
If it was not listed as one of the items the landlord is responsible for, the dafault is, the tenant is responsible. However, find out what the meter setup is like. If your apartment has its own meter, you may be responsible, but where you will share common meter with other tenants, you can argue that the landlors is responsible since you cannot be responsible for other tenants' utility use. Why not find out from your landlord, it could be an innocent omission that can be fixed.