Introducing oatmeal

Okay so she’s 4 months. Doctor said I can start introducing oatmeal out the bowl. Now she already has oatmeal in her bottles due to her acid reflux so exactly how would I do this? Still keep the oatmeal in her bottles and try feeding the oatmeal out the bowl for morning and evening feeding? And does she eat the oatmeal plus have her bottle? I haven’t done this in over 7 years so I can’t remember. Any pointers please