I'm pretty sure that people who know better than me have said that you shouldn't ever use levers to put tyres onto rims.
Then do it properly.
Start by putting in the tyre 6 o'clock from the valve.
As you move along up to the valve (putting them in side by side with your hand), when you're nearing to the valve, push the valve itself inward to shove the inner tube into the tyre so it'll be out of the way of the lever.
Then use tyre lever to push the final bit of tyre in (if you find it too hard with your thumb).
When that's done, pump it up a bit, then check by grabbing the tyre to reveal the rims tape - if there's no black inner tube peaking out between the rims and the tyres, now you can pump it up properly.
Then do it properly.
Start by putting in the tyre 6 o'clock from the valve.
As you move along up to the valve (putting them in side by side with your hand), when you're nearing to the valve, push the valve itself inward to shove the inner tube into the tyre so it'll be out of the way of the lever.
Then use tyre lever to push the final bit of tyre in (if you find it too hard with your thumb).
When that's done, pump it up a bit, then check by grabbing the tyre to reveal the rims tape - if there's no black inner tube peaking out between the rims and the tyres, now you can pump it up properly.