Hey, ! My name is MD. SAYEED and I am a graphics and web designer with 8 years of experience. I understand from your description that you are looking for a proficient Shopify developer to resolve the issue with your webshop that occasionally causes an error message to appear stating Required parameter missing or invalid: items. I can confirm that this issue occurs intermittently and that a Zoom call would be necessary to provide a detailed explanation of the problem.
I have extensive knowledge of HTML, WordPress, Shopify and other related technologies which make me well-suited for this job. My skills include graphics design, wordpress web development, shopify development and more specifically conversion of PSD to HTML which is essential for this project as it requires deep understanding of source code. Additionally, I have extensive knowledge in SEO, Google Adverts and web template design which will be beneficial when it comes to removing bugs from your webshop.