delete https://your-tenant-name.tenant.userclouds.com/userstore/config/columns//softdeletedretentiondurations/
This endpoint deletes a specific SoftDeleted column purpose ColumnRetentionDuration for a tenant column. SoftDeleted data is data that has been deleted but is retained for a specified purpose and duration after deletion. Once the column purpose retention duration has been deleted, it will fall back to the associated purpose retention duration.