On the Clergy Residence Deduction, Part A & Part B apply to my husband. He receives an amount in Box 30 as a housing allowance, and we own our home. Do I fill in both?

If you own the home you are receiving the allowance for, claim that allowance as income.

See links below from TurboTax Tips for more details:

Reporting Housing and Utility Allowances for Members of the Clergy: https://turbotax.intuit.ca/tips/reporting-housing-and-utility-allowances-for-members-of-the-clergy-5378

Clergyman’s Housing Allowance: https://turbotax.intuit.ca/tips/clergymans-housing-allowance-5415

Furthermore, these directly from the CRA.

Line 104 - Clergy’s housing allowance and/or an amount for eligible utilities:

https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/payroll/benefits-allowances/boarding-lodging/housing-utilities/clergy-residence.html

Clergy residence:

https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/personal-income/line-104-other-employment-income/line-104-clergy-s-housing-allowance-amount-eligible-utilities.html