My dog Bus came to me with ok ball drive, but zero interest in tug. He's pretty handler soft, so he wanted little to do with the "conflict" of it, and didn't understand that it was all in fun. I would reward him (giving him the toy back, patting/praising, then outing him and throwing toy) for merely holding the ball for longer periods of time after I put my hand on it, then narrowed the criteria to him actually pulling on it, then only for a good tug effort. He now tugs like a fiend, and can be stubborn about outing off the toy.
I would perhaps try that if there's anything he likes to mouth/carry, and work on building general toy drive by building the value of a few toys. I sometimes reward my boy for a good tug session on a toy he finds less than thrilling by producing a tennis ball during the reward phase. It's funny, now if he sees people struggling to pull a heavy item, he feels like he should join in... this has resulted in some interesting yard cleanup and fishing experiences!
I've had decent luck with using the flirtpole to "wake up" a couple dogs who had limited interest in toys, particularly by holding or tying them back while playing with another dog, then allowing them only a short session (just enough so they get the taste for it) before retiring it.
If he has no toy drive at all, but decent food drive, there are some toys which dispense food as a reward for tugging/play, so you could use that to teach the act of tugging, then transfer to something else if/when he gets the hang of it.
You can probably shape the act of pulling back on a rope held in mouth, and with enough repetition/reward/excitement, build that behavior into tug as play/reward, but I've never tried that.
Hopefully someone else has more suggestions and/or video for you, I've been lucky in that most dogs I've messed around with training have had at least some innate toy drive.
