#!/bin/bash

occ_command() {
check_command sudo -u www-data php "$NCPATH"/occ "$@";
}

occ_command fulltextsearch:configure "{"search_platform":"OCA\\FullTextSearch_ElasticSearch\\Platform\\ElasticSearchPlatform"}"
occ_command fulltextsearch_elasticsearch:configure "{\"elastic_host\":\"http:\\\\${NCADMIN}:${ROREST}@localhost:9200\"\,\"elastic_index\":\"${NCADMIN}\"}"
occ_command files_fulltextsearch:configure "{\"files_pdf\":\"1\"\,\"files_office\":\"1\"}"
occ_command fulltextsearch:index

gives me

$ shellcheck myscript

Line 7:
occ_command fulltextsearch:configure "{"search_platform":"OCA\\FullTextSearch_ElasticSearch\\Platform\\ElasticSearchPlatform"}"
                                        ^-- SC2140: Word is of the form "A"B"C" (B indicated). Did you mean "ABC" or "A\"B\"C"?
                                                          ^-- SC2140: Word is of the form "A"B"C" (B indicated). Did you mean "ABC" or "A\"B\"C"?

Line 8:
occ_command fulltextsearch_elasticsearch:configure "{\"elastic_host\":\"http:\\\\${NCADMIN}:${ROREST}@localhost:9200\"\,\"elastic_index\":\"${NCADMIN}\"}"
>>                                                                                                                    ^-- SC1117: Backslash is literal in "\,". Prefer explicit escaping: "\\,".

Line 9:
occ_command files_fulltextsearch:configure "{\"files_pdf\":\"1\"\,\"files_office\":\"1\"}"
>>                                                              ^-- SC1117: Backslash is literal in "\,". Prefer explicit escaping: "\\,".

$