So displaying the acf field {acf_prix} when on page with post ID 35 is working fine (outside and inside the form), but doesn’t work with {brf_acf_field:acf_prix:35}.
It’s working fine now when you force the post ID, but doesn’t work with {brf_acf_field:prix} or {brf_acf_field:prix:}, but anyway, I need it to work whith post ID specified so problem resolve.