As a parent, getting news like this is frightening. My heart goes out to your child, you and your family for all the uncertainty you must feel right now.
Where would be the closest country you could travel for his treatment? Would your child’s current doctor be able to refer your child elsewhere?

Because he needs immediate care, have you considered trying a Medical College Hospital in your own country? Protocol for treating lymphoma is fairly standard and you’d avoid having to get all the paperwork in order and trying to find another clinic in a foreign country on short notice. And with Covid, travel becomes challenging.

I found several Medical College Hospitals in Bangladesh. Since I’m not familiar with your country, I don’t know what is closest to you. However, Dhaka has several hospitals affiliated with medical colleges. The two I researched a little seem to have good reputations and possibly able to give your son more immediate care.
Would you consider finding treatment for your little boy closer to home? One of my oncologists is from Bangladesh and he’s excellent. Why was it recommended to find assistance elsewhere?

Bangladesh Medical College Hospital.
+880 2-44812101

Specialized Hospital https://bdspecializedhospital.com/department/oncology

I’m also giving you the link to contact Mayo Clinic. We have 3 campuses in the United States. Rochester, Minnesota. Phoenix, Arizona and Jacksonville, Florida
http://mayocl.in/1mtmR63