He wants to propose to her, but she asked him to speak to her before he approaches her wali (guardian)
Question

                There is a young man who is looking for a wife. He was told about a sister for marriage, but when he sent someone to speak to her about the matter, she asked to speak to him first, before giving him the address [of her father] and giving him permission to enter her house. Is it permissible for him to talk to her even over the phone, so that she can put her mind that rest, give him the address of the house and give him permission to speak to her wali? Is the ruling different if he goes with his mother or sister and meets her in a public place, without them being alone together, and he speaks to her in the presence of his mother or sister?
Praise be to Allah.If the woman is good in terms of religious commitment and character, and this young man definitely wants to propose to her, then there is nothing wrong with speaking to her over the phone, or meeting her in the presence of the mother or sister of the suitor, so long as they speak only as much as is necessary. Perhaps she wants to make sure about something, or to disclose something about herself so that the suitor will be fully informed. Once the desired purpose is achieved, then they must stop speaking, regardless of whether the proposal goes ahead or not.
The ruling on correspondence or conversation between potential spouses has been discussed previously. Please see the answers to questions no. 36807 and 45668.
And Allah knows best.