I deleted it by accident and have made many changes to package.json since. An npm install or npm update do not generate package-lock
package.json
npm install
npm update
package-lock
If your npm version is lower than version 5 then install the higher version for getting the automatic generation of package-lock.json.
Example: Upgrade your current npm to version 6.14.0
npm i -g npm@6.14.0
You could view the latest npm version list by
npm view npm versions