On 6-quart Instant Pot®, select SAUTE; adjust to normal. Melt butter in insert. Add onions, poultry seasoning and salt; cook 6 to 8 minutes, stirring occasionally, until softened. Select CANCEL.
Stir in celery and carrots. Stir in broth and chicken. Secure lid; set pressure valve to SEALING. Select MANUAL; cook on high pressure 2 minutes. Select CANCEL. Set pressure valve to VENTING to quick-release pressure.
Meanwhile, separate dough into 5 biscuits. Cut each biscuit into 8 pieces. Set Instant Pot® to SAUTE, normal temperature. Stir in whipping cream; heat to simmering. Stir in biscuit pieces; cook 4 to 6 minutes, stirring frequently, until dumplings are cooked through and liquid thickens.