Problem in fetching token for multiple clients

I am using angular 11 with keycloak version 12.0.2.
I have a single realm which has multiple clients and i want to implement a feature explained below.

  1. I login with one clientid

  2. once logged in user will get list of application in dropdown.

  3. Once user select any application i want to fetch token for that application so that i can load data related to that.
    So to fetch the token when user selects any app, i am using below method and passing the proper client id but it is not authorising the client.
    this.keycloakConfig.clientId = selected client id
    this.keycloakAuth = Keycloak(this.keycloakConfig);|

     			config: this.keycloakConfig
     		}, {
     			checkLoginIframe: false,
     		.then(() => {})

Is there any method to have seamless sso in keycloak.