We used a booster seat at that age, different variants are available (higher/lower/ with or without buckle)

I bought my dd from target $50 and best thing I did. This one has a high back also so it won’t hurt their neck

At 3 years of age most kiddies like to sit up at the grownups table so the toosh coosh sounds ideal! My 3 older grandkids have their own kiddy furniture at Grandma’s but still end up on our laps!

I got one from aldi’s a while ago. Its a clothe seat which straps on to most chairs and has the safety belts so they dont fall out. I take it out everywhere with us and have it in my boot in case we are going out for lunch or tea.

My son no longer has a high chair but uses a Toosh Coosh to give him height at the table (moulded plastic seat), and you can also get similar with straps if needed.