MEDIUM_RECTANGLE not working inside content

[jpnathannew]

Tried to place the MEDIUM_RECTANGLE Banner ad into my code and It is showing smart banner ad and its comming into center place

i am using IONIC Capacitor

const showTabBarBanner = () => {
    const options: AdOptions = {
      adId: 'ca-app-pub-XXX/XXX',
      adSize: AdSize.MEDIUM_RECTANGLE,
      position: AdPosition.CENTER,
    };

    // Show Banner Ad
    AdMob.showBanner(options)
      .then(
        async (value: any) => {
          await Toast.show({
            text: ''
          })
        },
        (error: any) => {
          console.error(error); // show error
        }
      );
    // Subscibe Banner Event Listener
    AdMob.addListener('onAdLoaded', async (info: boolean) => {
      console.log('Showing TabBar Banner AD.');
    });
  }

I want to show 300x250 ad into my content. can you please help me on this.