It is definitely ideal for your baby to have a place to rest their feet (for stability and eating safety), whether or not it comes with the original highchair. There are options to attach a flexible band or sling type foot rest to your chair that allow for height adjustment as well. For example, you could tie a thick rubber exercise band around the front legs of your high chair so that it sits at the proper height for your child’s feet. There are many foot rest attachments available for the IKEA Antilop high chair such as this bamboo foot rest attachment on amazon. Another option could be to find a box scootch up to the front high chair legs that allows your babies feet to rest with their knees at 90 degrees. Fill the box with soup cans so that your little one can’t kick it away and it sits sturdy in its place!