Arrow not visible

I’m not a professional developer. I’ve read the documentation in detail (most of it is way over my head), looked at several Google entries, and can see how to turn the arrow off, but not how to turn it on. If it’s on by default then I’ve somehow overwritten the default.

My main settings
Style: None
Tag Attribute: span
Trigclass Attribute: (null)
Tabindex Attribute: 0
Targtag Attribute: div
Targclass Attribute: (null)

Custom CSS:

.collapseomatic {
    font-family: "PT Serif", Georgia, serif;
    font-weight: normal;
    font-size: 22px;
    color: #d2692b;
}

I hope that’s sufficient info for someone to help me.

Thanks in advance.

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