Does prayer become invalid if one does not pay attention to the necessity of reciting Al-Fatiha with tajweed, and will Allah answer the supplication that it not be invalidated?

The obligatory aspect of Tajwid is to pronounce the letters from their correct articulation points and to give them their due rights and characteristics. As for embellishments like madd (prolongation) and ghunnah (nasalization), a deficiency in them does not affect the validity of the prayer. If you doubt the validity of your prayer, the default assumption is its validity. However, if you are deficient in some letters of Al-Fatiha, you must learn the obligatory aspects and not repeat such an error. There is a difference of opinion regarding the obligation of making up (qada') such prayers.