It depends on your package.
Monthly packages run a month at a time: Single Basic, Team Starter and Team Plus. You renew each month to carry on.
Three-month packages cover a full quarter: Single Pro and Team Premium. You deal with payment once every three months.
Nothing renews automatically. There is no stored card and no auto-charge, so renewing is always an active choice you make. You renew the same way you paid the first time. Reminder emails are sent to your registered email address to let you know that your listing will be expiring soon and when it has expired. See how to pay.
Renew before the end date, not after. When a paid subscription expires, the listing is unpublished and stops appearing in search until you renew. It is not deleted and your content is kept, but it is not visible to couples in the meantime. What happens when my subscription expires sets out exactly what is kept, for how long, and how to bring the listing straight back.
A free listing never needs renewing. Single Free stays published indefinitely unless you unpublish or delete it yourself.
If renewing every month is the annoyance, that is what the quarterly packages are for. Single Pro at UGX 140,000 covers three months and adds top placement and the Verified badge, so most vendors who find monthly renewals tiresome end up there. Compare the packages.