How to implement a R & Graphql process that checks the existence of next pages combining the results?

Question

How to implement a R & Graphql process that verifies the existence of next pages by combining the results?

I described a process that returns OK when the query is a text but returns error when I try to compose the received variable in the first query to get the following pages

1. The text of the queries for POST in Graphql is declared without the use of the backslash " "
2. The PASTE operation places the exhaust sequences
3. The first query is OK but the second returns status 400
4. However, the same query, with double quotes only in the endCursor value returns OK no when performed in Graphql or via Postman

For this reason, I suspect that the error received in the second query is related to formatting the escape sequences

References: Pagination (Handling multi-page Sponses) in https://rdrr.io/cran/httr/f/vignettes/api-packages.Rmd

[1] connected setup and queries

base_url <- "https://app.pipefy.com/queries"

token_api <- "Bearer eyJ0eXAiOJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJ1c2VyIjp7ImlkIjozMDEwMzM3NzQsImVtYWlsIjoiY2FybG9zLm9saXZlaXJhanVuaW9yQGNsYXJvLmNvbS5icisImFwcGxpY2F0F0aW9uIjozMDAwODMzDJ9fQ.L---------------ETC...

initial consultation

consulta_node <- '{"query":"{allCards(pipeId:301370952 first:50){pageInfo {hasNextPage endCursor}edges {node {id title fields { indexName report_value}}}}}"}'

terms of the following consultations for the interim argument of next page

consulta_node1 <- '{"query":"{allCards(pipeId:301370952 first:50 after:"'

query_node2 <- '"){pageInfo{hasNextPage endCursor}edges{Node{id title current_phase{id name}Fields{indexName name report_value}}}}}"}'

[2] perform the first query and get the information for next pages

consulta_node

res_api <- POST( url = base_url, add_headers(.headers = c("Content-Type"="application/json","Authorization"=token_api), body = query node, Encode = "json", Handle = NULL)

res_api

Response [https://app.pipefy.com/queries] Date: 2021-02-25 09:37 Status: 200 Content-Type: application/json; charset=utf-8 Size: 99.8 kB

resposta_json <- fromJSON(rawToChar(res_api$content), Flatten = TRUE,)

recovers data received

endCursor <- resposta_json[["date"]][["allCards"][["pageInfo"][["endCursor"]] endCursor

[1] "Wyizljailci3ljaildm4odixodu2of0"

hasNextPage <- resposta_json[["date"]][["allCards"][["pageInfo"]["hasNextPage"]] hasNextPage

[1] TRUE

[ 3] assemble next query including endCursor

the following queries <- Paste(querie_node1, endCursor, consult_node2, Sep = "") following consultations

executes the query with indication of next page

res_api <- POST( url = base_url, add_headers(.headers = c("Content-Type"="application/json","Authorization"=token_api), body = following queries, Encode = "json", Handle = NULL)

res_api

Response [https://app.pipefy.com/queries] Date: 2021-02-25 09:37 Status: 400 Content-Type: text/html; charset=utf-8

Thank you