Upvote:1
It appears you will need a visa because you are not a citizen of Denmark (who have visa free entry to The Gambia) but of Afghanistan
Visa exemption
Nationals of the following 104 countries and territories can visit the Gambia without a visa for up to 90 days (unless otherwise noted)
Afghanistan is not on the visa free list, **neither is an exemption mentioned for permanent residents of visa free countries mentioned.
On their UK Embassy website it says:
Citizens of the United Kingdom, the Commonwealth, the Economic Community of West African States (ECOWAS) and other nations with a reciprocal via abolition agreement with the Gambia do not require a visa to enter the country; whether on holiday or on a business trip not exceeding 90 days.