Hi Amaaz Arshad!
I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this! Since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others ", I'll repost your solution in case you'd like to accept the answer.
Ask: Icons not appearing in azure webapp
Solution: Customer suspected issue on icon packages side. The issue was later resolved by adding below line to include the CDN for icons as mentioned in this Github thread
initializeIcons( 'https://res.cdn.office.net/files/fabric-cdn-prod_20240129.001/assets/icons/', );
If I missed anything please let me know and I'd be happy to add it to this answer, or feel free to comment below with any additional information.
If you have any other questions, please let me know. Thank you again for your time and patience throughout this issue.
Please don’t forget to Accept Answer and Yes for "was this answer helpful" wherever the information provided helps you, this can be beneficial to other community members.
Thank You.