Currently there isn't a way to Import or Export in the LastPass mobile apps, I have asked our team and they are currently working on a way to allow Free users with their device type set to Mobile to be able to Import using the LastPass website on desktop, while we're not sure when this will happen in the meantime we can add extra device type switches to your account so that you can switch your Device type to desktop, Import, then switch back to Mobile as your active device type. So that we can add those switches and so that you don't post any private account information publicly, could you send me a private message with your LastPass account email address? To send me a private message, please click my username to view my profile, then click the blue "Send a Message" button in the upper right.
I am also facing same issue, i need to export the vault but can't as its fixed with my mobile only now. Please allow me 1 switch do that i can export from my desktop login. Please let me know how and where to share my user id.