I used that cron job in other firmware (asus merlin) and I would like to know if it possible to use here, if I can fit it here?
# DNSCrypt-proxy Restart every day @ 10.05
cru a DNSCryptRestart "5 10 * * * /jffs/dnscrypt/manager dnscrypt-start" #DNSCrypt_Restart#
Cron jobs can surely be used in openwrt. But the question is if you have
DNSCrypt-proxy installed on your Openwrt installation. If yes and if you still want to restart it with a cronjob you just need to adapt the command to reinstall it.
Generally there's no reason to restart services that work properly.
If you have specific issues, it's best to discuss them before applying workarounds.
someone gave me that cron job in the time for randomization(for relays), to restart the proxy to randomize relays used.
yes it is, I installed the package dnscrypt-proxy on my build
Then readup the doc I linked above and adapt the command. Most likely it be
/etc/init.d/dnscrypt-proxy restart assuming that it is a proper service on openwrt.