Hi Vo,
Thanks for reaching out. You could use the ID of the user list to identify the user list in the criterion and then apply the User List criterion in the campaign. A User List criterion represents a user list that is defined by the advertiser to be targeted. Positive and negative criteria are supported at the campaign level. The CampaignCriterionService allows you to specify targeting at the campaign level for the UserListInfo type.
Thanks and regards,
Xiaoming, Google Ads API Team