https://unitedairlinesoddohelp.helpshift.com/hc/faq/654-is-there-any-way-to-add-a-lap-infant-ticket-online-on-american/
https://unitedairlinesoddohelp.helpshift.com/hc/faq/655-can-you-add-a-infant-seat-after-booking-a-american-airlines-flight/
https://unitedairlinesoddohelp.helpshift.com/hc/faq/656-will-american-airlines-seat-me-with-my-child/
https://unitedairlinesoddohelp.helpshift.com/hc/faq/657-what-happens-if-i-don-t-select-a-lap-child-seat-on-american/
https://unitedairlinesoddohelp.helpshift.com/hc/faq/658-how-to-add-baby-seat-to-american-flight/