To work with Bitcoin you need node. You can create your own node.
To turn on Bitcoin make the following changes in the configuration file:
# global/config.yaml
...
# enabled paymentInterfaces - true
paymentInterfaces:
enabled: true
...
# select currency name
bitcoin:
# select currency id and turn on it
id: "BITCOIN-PI"
enabled: true
...
# To change the Bitcoin logo or resize, use logo_url
logo_url: "https://raw.githubusercontent.com/nsart/coin-logos/master/btc.png"
...
network: testnet
rpchost: bitcoind
rpcport: 18332
rpcuser: admin
rpcpassword: password
port: 18333
...