2 different issues there, RE Electron / Capacitor SQLite: haven't tried myself, but Capacitor SQLite advertises Electron support with some caveats - did you read the Electron Quirks blurb in the README?

Also worth a read: https://github.com/capacitor-community/sqlite/blob/89ffbee450eea5152a30863c4dc8f3158446fab2/docs/ElectronBetterSQLite3.md

I temporarily resolved this problem by manually editing the rt/electron-plugins.js file which after npx cap sync electron adds CapacitorSQLitePlugin but it resolves the plugin from the project's root node_modules instead of electron's node_modules which was giving this error as better-sqlite3-multiple-ciphers is not present in parent node_modules but electron-plugins.js gets overridden when again running npx cap sync electron.

I managed to avoid this error by not converting electron-plugins.js file to ES6 module