Hi there @peterjf2,

You would need to pass the CA certificate to your application as an environment variable.

You can refer to the CA_CERT variable which holds the CA certificate for the Managed databases.

For more information on how to use the environment variables on the App platform, I could suggest taking a look at the official documentation here:

https://www.digitalocean.com/docs/app-platform/how-to/use-environment-variables/

Hope that this helps.
Regards,
Bobby

Okay, for anyone else who gets stuck on this, I had to put the entire cert into double quotes and add a \n after each line.

So now my database connection code looks like

const { Pool } = require('pg')
const fs = require('fs')

const pgPool = new Pool({
user: process.env.PGUSER,
password: process.env.PGPASSWORD,
host: process.env.PGHOST,
database: process.env.PGDATABASE,
port: process.env.PGPORT,
ssl: {
    rejectUnauthorized: true,
    // ca: fs.readFileSync(
    //     `${process.cwd()}/cert/ca-certificate.crt`.toString()
    // ),
    ca: process.env.CA_CERT,
},
})
.on('connect', () => {
    console.log('connected to the database!')
})
.on('error', (err) => {
    console.log('error connecting to database ', err)
})

with the CA_CERT env for dotenv and my App Platform looks like:

CA_CERT="-----BEGIN CERTIFICATE-----\nVALUES HERE WITH NO SPACES AND A \n 
AFTER EACH LINE\n-----END CERTIFICATE-----"

I go a little bit more into detail in my stack overflow question here:
Example link

I do not think it is possible to do this with the $7 development database as I was unable to find a CA_cert anywhere to download. Would probably just have to leave the unauthorized portion as false.