My notes on converting Cisco Catalyst 9105, 9115, 9xxx series access points to autonomous AP with embedded wireless controller.

Connect to your AP with console cable.

User: Cisco
Pass: Cisco
Enable: Cisco

Setup connectivity betweeen TFTP (in my case running on windows PC – tftpd64) server and AP.

TFTP server IP: 192.168.1.1/24
AP IP: 192.168.1.2/24

capwap ap ip 192.168.1.2 255.255.255.0 192.168.1.1

#version <= 8.9:

ap-type mobility-express ap-type ewc-ap tftp://192.168.1.1/ap1g7 tftp://192.168.1.1/C9800-AP-iosxe-wlc.bin

#version > 8.9:

ap-type ewc-ap tftp://192.168.1.1/ap1g7 tftp://192.168.1.1/C9800-AP-iosxe-wlc.bin

The conversion begins …

Would you like to enter the initial configuration dialog? [yes/no]: enter no

 The enable secret is a password used to protect
  access to privileged EXEC and configuration modes.
  This password, after entered, becomes encrypted in
  the configuration.
  -------------------------------------------------
  secret should be of minimum 10 characters with
  at least 1 upper case, 1 lower case, 1 digit and
  should not contain [cisco]
  -------------------------------------------------
  Enter enable secret: 

[0] Go to the IOS command prompt without saving this config.
[1] Return back to the setup without saving this config.
[2] Save this configuration to nvram and exit.

Select 0

conf t
hostname C9800

Create admin user – also used for web GUI:

user-name admin
priv 15
password test123

Set ap profile:

ap profile ap-default

Configure management user for access points:

mgmtuser username admin password 0 test123 secret 0 test123

Configure management IP address (you will access it via SSH or web GUI):

interface gigabitEthernet 0
ip address 192.168.1.2 255.255.255.0
no shut
ip default-gateway 192.168.1.1

Enable web server and save config:

ip http secure-server
wr

Access EWLC via https://192.168.1.2

All commands together after conversion is done:

WLCA49B.FFFF.BEEF#configure terminal
WLCA49B.FFFF.BEEF(config)#hostname C9800
C9800(config)#user-name admin
C9800(config-user-name)#priv 15
C9800(config-user-name)#password test123
C9800(config-user-name)#ap profile ap-default
C9800(config-ap-profile)#$mgmtuser username admin password 0 test123 secret 0 test123
C9800(config-ap-profile)#interface gigabitEthernet 0
C9800(config-if)#ip address 192.168.1.2 255.255.255.0
C9800(config-if)#no shut
C9800(config-if)#ip default-gateway 192.168.1.1
C9800(config)#ip http secure-server
C9800(config)#do wr
Building configuration...
[OK]
C9800(config)#

reference: https://www.youtube.com/watch?v=NBt370eiQ3I