At Hostinger, SSH access is available for Premium or above hosting plans!
When you first set up your account, you created an FTP password. This is the same SSH password as well. If you change your main domain's FTP password, it will also set the same value for SSH password automatically.
In case you want to change only the SSH password so that you have a different password to connect to SSH than FTP, you can achieve it by following these steps:
Open Hosting → Manage:
Go to the Advanced section and select SSH Access:
And click on Change next to Password:
You will be prompted to generate a new password containing numbers, symbols, uppercase and lowercase letters. Once done, click Change:
That's it! Now you have a new password to access all of your account's files via SSH.