When providing only a single string as an abstract, e.g.:

#show: template.with(
  abstract: lorem(50),
)

or

#show: template.with(
  abstract: "This is an abstract",
)

the compile breaks with

typst compile examples/pixels/main.typ --root .
error: type dictionary has no method `map`
    ┌─ lapreprint.typ:278:14
    │
278 │     abstracts.map(abs => {
    │               ^^^

The same happens if the abstract text is wrapped as content [This is text] rather than a string.

I think this is happening because line 270-271 of lapreprint.typ returns a dictionary, but the abstracts.mapin line 278 requires an array.