Lightroom - LrHttp doesn't get executed

Question

Currently i'm making an plugin for Lightroom that basically has to login a user and help him uploading pictures to a website. Unfortunately I've got stuck in the following problem:

• The LrHttp seems not to work. It gaves me a 'nil' value after it gets 'executed'.

I know that usually requests needs a little time to get executed and thought it could be a problem with LrHttp already running while the rest of the code kept running as well. So, I looked for ways to get the LrHttp running synchronously but unhappily with no success.

Below you guys can see the part of the code that seems not to work - the function Picsize.login(email, password).

if doingLogin then return end
doingLogin = true

LrFunctionContext.postAsyncTaskWithContext( 'PICSIZE login',

function( context )

    if not propertyTable.LR_editingExistingPublishConnection then
        notLoggedIn( propertyTable )
    end

    propertyTable.accountStatus = LOC "$$$/Picsize/AccountStatus/LoggingIn=Entrando..."
    propertyTable.loginButtonEnabled = false

    LrDialogs.attachErrorDialogToFunctionContext( context )

    context:addCleanupHandler( function()

        doingLogin = false

        if not storedCredentialsAreValid( propertyTable ) then
            notLoggedIn( propertyTable )
        end

    end )

    local email, password = PicsizeAPI.getCredentials()

    if authRequestDialogResult == 'cancel' then
        return
    end

    propertyTable.accountStatus = LOC "$$$/Picsize/AccountStatus/WaitingForPicsize=Aguardando uma resposta da plataforma PICSIZE..."


    -- this piece seems not to work
    local token = PicsizeAPI.login(email, password)

    if not token then
        return
    end

    local userData = PicsizeAPI.getUserData(token)

    if not userData then
        return
    end

    propertyTable.display_name = userData.display_name
    propertyTable.display_email = userData.display_email
    propertyTable.token = token

    PicsizeUser.updateUserStatusTextBindings( propertyTable )

end )

And inside the function Picsize.login(email, password) we have:

local request = getFormatedRequest(
    '/auth/login',
    { email = email, password = password },
    {{ field = 'Content-Type', value = 'application/json' }}
)

local response, headers = LrHttp.post(request.url, request.body, request.headers)

if response then
    return response.token
else
    return nil
end

I'll be so grateful if someone helps me or give some tips to overcome it :) Thanks!