Mikrotik Router53 DDNS

Add global variable

/system script add name=params source={
:global apiKey "you-api-key";
:global Secret "you-share-secret"
:global ddnshostname "example.com.";
:global ddnsserv "update.example.com"
}

Add scheduler

/system scheduler add name=global-scripts start-time=startup on-event="/system script {run md5sum; run params; run ddns_route53;}"
/system scheduler add name=ddns-update interval=30m on-event="/system script run ddns_route53"

Ref

1. Script MD5 Hash Generator
2. Dynamic DNS Update Script for Namecheap