Keep submitting a webform, and mention about you got married and wanted to add your spouse. They will send you an ADR with relevant documents needed.
Meanwhile, prepare following documents for spouse
1. Marriage Certificate
2. Valid Passport (validity should be more than a year considering the processing time at IRCC)
3. Govt. IDs like Driver License
4. Photos of each ceremony during marriage
5. Photos of meeting spouse before marriage at different spots
6. Photos with spouse and parents (yours and spouse's)
7. Wedding Invitation Card
Rest wait for IRCC to respond.