default created_via="backend"

src/models/entities/Participant.ts

@@ -78,7 +78,7 @@ export abstract class Participant {
   /**
    * how the participant got into the system
    */
-  @Column({ nullable: true })
+  @Column({ nullable: true, default: "backend" })
   @IsOptional()
   @IsEmail()
   created_via?: string;