The 2002 Ford F-150 with a manual transmission has a transmission fluid fill plug located on the side of the transmission case. It's usually a smaller bolt, often near the top. You'll need a shop manual or a detailed diagram specific to your truck's transmission (e.g., BorgWarner T-176, etc.) to pinpoint the exact location.
Do not rely solely on visual inspection. Incorrectly adding fluid through a similar-looking plug (like a drain plug) can seriously damage the transmission. Using a shop manual or a reliable online resource with diagrams for your specific transmission model is crucial for proper identification.
