You would need to create a custom workflow to handle this.

https://our.umbraco.com/documentation/Add-ons/umbracoforms/developer/extending/adding-a-workflowtype

Hi Stefan,

Yes, we can do this by creating a custom workflow, once the workflow is created then it will be listed in the workflow section of the Umbraco form, then just configured the created workflow to the corresponding form.

But keep in mind that the form data will save even if there is an issue occurred at the time of posting the data to HubSpot.

Example

 public class CustomFormFlow : WorkflowType
    {

        public CustomFormFlow()
        {
            this.Id = new Guid("ccbeb0d5-adaa-4729-8b4c-4bb439dc0203");
            this.Name = "Custom Workflow ";
            this.Description = "This is a custom workflow";
            this.Icon = "icon-flash";
            this.Group = "Services";
        }
        public override WorkflowExecutionStatus Execute(Record record, RecordEventArgs e)
        {
            try
            {

              //param `record` has all the data
           //you can read the value 
           record.GetRecordFieldByAlias("aliasName")?.ValuesAsString();
var status=postDataToHubspot();
                if (status)
                    return WorkflowExecutionStatus.Completed;
                else
                    return WorkflowExecutionStatus.Failed;
            }
            catch (Exception ex)
            {
                Current.Logger.Error<CustomFormFlow >(ex, "Error in CustomFormFlow ");
                throw;
            }
        }

Regards Dhanesh ;)

is working on a reply...