Step 1: 

Open your Huawei AppGallery and search for NowServing by SeriousMD.

Step 2: 

Look for the Results from Petal Search at the bottom, you should be able to see the NowServing app.

Step 3: 

Download the APK. 

A prompt like the one below will appear. Click the DOWNLOAD option. You do not have to worry, it does not contain any viruses.

Step 4: 

Allow all permissions and click INSTALL.

Step 5: 

After installing, go to the NowServing app info. Scroll down and click on the OPEN BY DEFAULT option.

Step 6:

On the "Open supported links in this app" tab, choose ALWAYS ALLOW.

And you're done! 

Congratulations! 

You can now use the NowServing app on your Huawei device! 🥳