how do I solve the missing modules problem in parse server - node.js

Question

I have installed the parse server and it runs the single command post/put correctly.
However, after I added the express.js framework, I used “npm start – /var/www/parse_server/config.json” to run the server.
Then, I got the following errors.
How do I install the missing modules? Thanks
(1to1call) Tom:parse_server mariolzx$ npm start -- /var/www/parse_server/config.json
> parse-server#4.5.0 start /private/var/www/parse_server/parse_server
> node ./bin/parse-server "/var/www/parse_server/config.json"
internal/modules/cjs/loader.js:969
throw err;
^
Error: Cannot find module '/var/www/parse_server/config.json'
Require stack:
- /private/var/www/parse_server/parse_server/lib/cli/utils/commander.js
- /private/var/www/parse_server/parse_server/lib/cli/utils/runner.js
- /private/var/www/parse_server/parse_server/lib/cli/parse-server.js
- /private/var/www/parse_server/parse_server/bin/parse-server
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:966:15)
at Function.Module._load (internal/modules/cjs/loader.js:842:27)
at Module.require (internal/modules/cjs/loader.js:1026:19)
at require (internal/modules/cjs/helpers.js:72:18)
at parseConfigFile (/private/var/www/parse_server/parse_server/lib/cli/utils/commander.js:93:24)
at Command._commander.Command.parse (/private/var/www/parse_server/parse_server/lib/cli/utils/commander.js:139:20)
at _default (/private/var/www/parse_server/parse_server/lib/cli/utils/runner.js:57:22)
at Object.<anonymous> (/private/var/www/parse_server/parse_server/lib/cli/parse-server.js:38:21)
at Module._compile (internal/modules/cjs/loader.js:1138:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10) {
code: 'MODULE_NOT_FOUND',
requireStack: [
'/private/var/www/parse_server/parse_server/lib/cli/utils/commander.js',
'/private/var/www/parse_server/parse_server/lib/cli/utils/runner.js',
'/private/var/www/parse_server/parse_server/lib/cli/parse-server.js',
'/private/var/www/parse_server/parse_server/bin/parse-server'
]
}
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! parse-server#4.5.0 start: `node ./bin/parse-server "/var/www/parse_server/config.json"`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the parse-server#4.5.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /Users/mariolzx/.npm/_logs/2021-02-28T01_57_37_051Z-debug.log
(1to1call) Tom:parse_server mariolzx$ npm start -- /var/www/parse_server/config.json