Here in the printer’s manuscript, Oliver Cowdery initially omitted the subordinate conjunction that after “it came to pass”. Virtually immediately he caught his error and supralinearly inserted the that, although initially he placed his insert mark before pass rather than after it. He caught this error immediately, erasing the improperly placed insert mark and placing it after the pass. As explained under Alma 21:10, that is optional after “it came to pass” when there is a following as-clause. Earlier in Alma 62 (see under verse 15), Oliver made the same error in 𝓟 (that is, he initially omitted the that). Note here in Alma 62:28 that the preceding verse also originally began “now it came to pass that as …” (Alma 62:27); although in verse 27 the as was omitted by the 1830 typesetter, the that has been maintained.
Summary: Accept in Alma 62:28 the corrected reading in 𝓟 with the subordinate conjunction that before the as-clause (“and it came to pass that as …”).