cryptsetup and automount

Hi;

I made a luck file and crypttab to open my crypt automatically but, if I post this, it's obviously not working ;)

my guide is this howto : https://www.howtoforge.com/automatically-unlock-luks-encrypted-drives-with-a-keyfile

with centos and debian it works well
but on alpine it works only with a script into : /etc/local.d/

So my questions are :
1. How I could tell Alpine to decrypt my drive with the info it could find in /etc/crypttab ?
2. If it's not possible; How I could prioritize my local.d script or how I could say to my services startAfter or startBefore like it's possible with SystemD

thanks for you help!

Jonathan