Every slide on modern RV's has a manual capability. It may be hidden under the black plastic underbelly, or in some it's over the inner molding at the top of the slide, other's it's through an access hole on the skirting opposite the slide. Possibly someone with the same model and year RV will answer your question with more specifics, but the general answer is, Yes, you have a manual capability, finding it may be more difficult, but it's there.
2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS