How to modify the behavior of the snippets?
desired behavior: https://user-images.githubusercontent.com/53343401/160498244-f9d7f329-de63-4b72-b2e5-0ee41fc5f09c.mp4
actual behavior: https://user-images.githubusercontent.com/53343401/160498345-34ecc612-6db1-454e-af13-36fba44bd426.mp4
in the desired behavior the placeholder text is replaced immediately I start typing, how can I get this?
Not exactly the same behaviour, but close that can be achieved by setting keymap = { recommended = true, jump_to_mark = '<leader><tab>' }.
Select the item, by pressing <tab> and press <leader><tab> to jump to the first place holder directly and edit it.
Select the item by pressing <leader><tab> to jump through all place holders and edit it.
Also, check https://github.com/ms-jpq/coq_nvim/pull/249 and related issues.