As PP said First Steps Nutrition is a great resource https://www.firststepsnutrition.org/vegan-infants
A toddler needs 13g of protein.
For food ideas, chickpea pasta from Aldi has 14g protein per 100g cooked and is pretty bland, DD is happy to eat it with tomato based pasta sauce and sweetcorn.
Mac n cheeze using nutritional yeast (8g protein in 2 tbsp) with vegan cream cheese, violife brand has B12 added, and blended butternut squash. Macaroni itself has about 7g protein per 100g once cooked and I add peas which have about 5g per 100g.
Baked beans have 6g protein per 100g as well as 2mg iron (toddlers need 7mg a day) sliced bread is also fortified with iron and is roughly 4g protein per slice dependant on variety.
I also do scrambled tofu on toast, tofu has lots of protein, I serve with tomatoes and cucumber.
Warburtons do seeded bagels that are higher in protein (8.1g per thin bagel) we sometimes have that with peanut butter (25g protein per 100g).
Lentil soup as PP said is good. Green leafy veg is great if you can get it into them even with soup (DD will eat broccoli and spinach soup).
We always have peanut butter and flaxseed (for omega 3) on cereal. Cereal like weetabix and Shreddies are great as they are fortified (including with iron).
Soya milk and soya yoghurts are also good sources of protein, choose some that are fortified with calcium.
We also have things like Richmond meat free sausages or green cuisine chicken dippers a couple of times a week. A recent study found that ultra processed meat substitutes had no negative effect on health (but processed meat did).
Obviously toddlers might not (won’t) eat anywhere near 100g of each of the listed foods but the point is they don’t need to, as long as they are offered a variety and eat some they will almost certainly get enough protein as 13g is easy to hit, and with enough fortified foods calcium and iron shouldn’t be an issue either. We also give a multivitamin in case.