What problems can excessive use of the H1 tag cause?

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Hello, I am just starting to learn SEO. I have read that I should not use multiple H1 tags in an article, but I am having trouble creating the table of contents I want with H2. For example, in this article, the main topic headings should be separate from each other, but when I use H2, they become mixed up in an irrelevant way, so I end up having to use multiple H1 tags. Would this have significant negative effects on SEO? What solutions would you recommend for this issue?