What is the ruling on the fast of a fiancée if a fluid, which is discharged from a woman during arousal, is released from her during a phone call in the daytime in Ramadan, and what is the ruling on the fast of the fiancé from whom nothing was discharged?

Your fast is valid without any issue. As for her, if the fluid that came out of her was maniy (seminal fluid), then her fast is invalidated, and she must make up for that day. If it was madhiy (pre-seminal fluid), her fast is not invalidated. If she is unsure whether what came out of her was madhiy or maniy, the default is that the fast is valid, and making up the day is not obligatory. You both must repent to Allah, for the fiancé is a stranger to his fiancée, and your conversation has exceeded the lawful limits and opened a door for Satan.