If you do not secure a valid job offer within your visa validity (120 days plus possible 60-day extension), you will be required to leave Portugal before your visa expires. Overstaying can result in fines, entry bans, or difficulties obtaining future visas.
If you are close to securing a job, you may be able to request an extension, but this is granted only once and at SEF’s discretion. You can reapply for a Jobseeker Visa in the future or explore other visa options, such as a Portugal Work Visa, if your circumstances change.