Bangladesh was not informed when KSA declared the Alliance. However We have sent troops in middle east before... In the Gulf war 2300 troops fought for Kuwait, 59 died. After the Lebanon war in 2006 they were the first to reach Lebanon even after Israel's objection against Bangladesh being the hostile nation. And we have continuous presence in Kuwait to safeguard it's interest.
We don't have fancy war toys. But our trained professionals proved their worth in 1965 1971 and in Chittagong Hill tracts.
And Bangladesh maintains that under the recently formed alliance Troops will only go to war only if Holy sites are threatened.