[SalesForce] LWC1041: Static id values are not allowed in iterators. Id values must be unique within a template and must therefore be computed with an expression

I recently had same need for the choose existing account results. I wanted to take control of which account fields were going to be shown in the search results when you click on "Choose Existing" field in the account section.

It is controlled by the "Search Layout" of the account object, specific for the current user profile.

Also if the Search Layout allows you to insert more fields, only the first 2 in the list will be shown in the choose existing account search results. The fist MUST be Account Name (you cannot deselect it or move 2nd). The second field is the one you will see immediately after the account name in the search results box (with a lighter fore color).

So I created a custom formula field named "Search Fields" and I used it for my user profile related search result in the second position (after account name).

Whenever you use for:each you have to use key attribute in the child markup. If not it gives a compilation error.

From SF Docs:

Note that you must use a key to assign a unique value to each item in the list.

<select class="slds-select" id="select-01">
     <template for:each = {listViews} for:item="listViewItem">
        <option key={listViewItem.key} value={listViewItem.key}>{listViewItem.value}</option>
     </template>
</select>