Connecting existing domain to lightsail

Hello.

If you already have a Static IP for Lightsail, I think you just need to set the domain with an A record for it.
In other words, create an A record for "martastour.com" on "Hostinger.com".
https://support.hostinger.com/en/articles/4468886-how-to-manage-a-records

If you use Lightsail's DNS zone, please change the NS record set for "Hostinger.com" to the NS record of your Lightsail DNS zone.
https://lightsail.aws.amazon.com/ls/docs/en_us/articles/lightsail-how-to-create-dns-entry

Hello! Since you were able to go through the guided website setup flow without creating an A record, it means that you likely chose to go with a DNS Zone managed by another service. If that is the case, you can add an A record in that third party service that points to your Lightsail instance's static IP as stated in above comment. Do you want to manage your Domain by a Lightsail DNS Zone? If so, have you updated your domain's nameserver records to match the Lightsail's DNS Zone's nameservers? For martastour.com, you should be able to find your DNS Zone's details here: https://lightsail.aws.amazon.com/ls/webapp/domains/martastour-com and copy your nameservers from there and paste replace it on the hostinger.com's management site. You should be able to learn more on how to do this on Hostinger here: https://www.hostinger.com/tutorials/how-to-use-hostinger-dns-zone-editor#:~:text=If%20you%20only%20purchase%20a,edit%2C%20add%2C%20and%20remove. After editing the nameservers, you can try restarting the website setup flow and choose a Lightsail DNS Zone this time and create an A record for mantasour.com and www.mantasour.com (if you want www to be supported as well). You can learn more about the website setup here: https://docs.aws.amazon.com/lightsail/latest/userguide/amazon-lightsail-tutorial-launching-and-configuring-wordpress.html?icmpid=docs_console_unmapped#set-up-wordpress-instance-website