A domain can only be renewed in the same registrar where it is currently registered, regardless of which hosting is used or where the domain is pointing.
If your domain is in another registrar and has more than 10 days before the expiration date, you can transfer your domain to Hostinger right away! Then, you will be able to perform the next renewals here at Hostinger 😊
In case your domain is expiring sooner, the recommendation is to renew your domain with your current domain provider before initiating a domain transfer - this will ensure a smooth procedure and prevent any service interruptions.
For expired domains, you can wait until the domain is available again, and register it here at Hostinger directly.