The following steps were used to top up Gitcoin's BrightID sponsorships as seen in the BrightID app dashboard.
Interacting with Sp and Subs is much cheaper on IDChain, but prices and availability of Sp and Subs may differ between mainnet and IDChain.
The gas token on IDChain is called Eidi and free supply is available from the Eidi faucet.
If Subs or Sp were purchased on mainnet, bridge them. If either Subs or Sp will be purchased on IDChain, bridge Dai. Use the IDChain omnibridge.
Mainnet Subs or Sp bridged in the previous step need to be converted to IdSp or IdSubs. This can be done from the sponsorship dashboard after switching networks to IDChain.
Subs are a stream of sponsorships (Sp), with new Sp available to be claimed immediately and every month thereafter for 6 years at a rate that increases every year. Use the "activate" and "claim" buttons to convert Subs into Sp.
See the sponsorship dashboard instructions for more information.