Can not connect docker hosted SSMS from containerized GraphQL api - node.js

Question

I am using SQL Server image as DB and trying to connect it with GraphQL api written using TypeORM. If I run docker-compose up -d it is simply runs the DB(I can connect it from local SSMS) but API is not able to connect it.
Dockerfile:
FROM node:14
# Create app directory
WORKDIR /usr/src/app
# Install app dependencies
COPY package*.json ./
RUN npm install
# Copy app source code
COPY . .
#Expose port and start application
EXPOSE 4000
CMD [ "npm", "run", "dev" ]
Docker-Compose File:
version: "2"
services:
server:
build: .
ports:
- "4000:4000"
depends_on:
- plhdashboardb
plhdashboardb:
container_name: plhdashboardb
image: mcr.microsoft.com/mssql/server:2019-latest
ports:
- "1434:1433"
environment:
SA_PASSWORD: "I_AM_mr_React"
ACCEPT_EULA: "Y"
Building it using docker build -t server . and running it using docker-compose up -d
If I try to run the URL http://localhost:4000/graphql, it never loads, but Server can be connected from local SSMS.
ormconfig.json:
{
"type": "mssql",
"host": "plhdashboardb",
"username": "sa",
"password": "I_AM_mr_React",
"database": "plhdashboardb_Dev_Mock",
"synchronize": true,
"autoSchemaSync": true,
"logging": false,
"options": {
"encrypt": true,
"enableArithAbort": true
},
"entities": [
"src/entity/**/*.ts"
],
"migrations": [
"src/migration/**/*.ts"
],
"subscribers": [
"src/subscriber/**/*.ts"
],
"cli": {
"entitiesDir": "src/entity",
"migrationsDir": "src/migration",
"subscribersDir": "src/subscriber"
},
"seeds": [
"src/database/seeds/**/*{.ts,.js}"
],
"factories": [
"src/database/factories/**/*{.ts,.js}"
]
}
If I enter the container docker exec -it server_server_1 bash and run npm run dev and getting this error:
(node:167) UnhandledPromiseRejectionWarning: ConnectionError: Failed to connect to localhost:1434 - Could not connect (sequence)
at Connection.<anonymous> (/usr/src/app/node_modules/mssql/lib/tedious/connection-pool.js:68:17)
at Object.onceWrapper (events.js:422:26)
at Connection.emit (events.js:315:20)
at Connection.EventEmitter.emit (domain.js:467:12)
at Connection.socketError (/usr/src/app/node_modules/mssql/node_modules/tedious/lib/connection.js:1290:12)
at /usr/src/app/node_modules/mssql/node_modules/tedious/lib/connection.js:1116:21
at SequentialConnectionStrategy.connect (/usr/src/app/node_modules/mssql/node_modules/tedious/lib/connector.js:87:14)
at Socket.onError (/usr/src/app/node_modules/mssql/node_modules/tedious/lib/connector.js:100:12)
at Socket.emit (events.js:315:20)
at Socket.EventEmitter.emit (domain.js:467:12)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:167) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:167) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
[nodemon] clean exit - waiting for changes before restart