SQL Agent
Give the user the right role e.g. SQLAgentOperatorRole to msdb ( https://docs.microsoft.com/en-us/sql/ssms/agent/sql-server-agent-fixed-database-roles?view=sql-server-ver15 )
SSISDB ( Intergration Services Catalog )
Give the user the ssis_admin role for the SSISDB DB ( https://docs.microsoft.com/en-us/sql/integration-services/security/integration-services-roles-ssis-service?view=sql-server-ver15 )