If that file is missing or corrupted it's possible that it's been damaged by malware or a virus. So start by carrying out a full scan with your anti-virus program. Then run an anti-malware scan. For that you can use the free version of Malwarebytes Anti-Malware if you've already got it on your computer. (I don't currently recommend downloading a fresh installation of that software though, as it now lands you with a free trial of the full product, which seems to slow some computers to a crawl). Otherwise use AdwCleaner, which is also from Malwarebytes
https://www.malwarebytes.com/adwcleaner/ or Microsoft's own scanning software:
https://docs.microsoft.com/en-us/windows/security/threat-protection/intelligence/safety-scanner-download
That should deal with any underlying problem but it won't replace the missing file. There are loads of websites which you download that file from but many of them will dump something nasty onto your computer at the same time, so you should only get it from the original software developer's site:
https://www.sqlite.org/download.html
(Scroll down to 'Precompiled Binaries for Windows'. Use the first download if you've got a 32-bit system or the second one for a 64-bit system. If you're not sure whether your system is 32-bit or 64-bit, click on 'Start', right-click on 'Computer' and select 'Properties').
That's a zip file, so you might need to extract it first in order to get to the installation file, which will put the missing dll back on your computer.
Alternatively, try one of the free online file conversion services:
https://www.techradar.com/uk/news/the-best-online-video-converter