If the ASA runs an old ASDM version (e.g., 6.4 or 7.2), you can access it via: https://<asa-ip>:443 (accept the self-signed certificate) Click "Run ASDM" to download a .jnlp file. Launch that with Java Web Start. From there, many versions allow you to install the standalone launcher via the Tools menu.
You do not typically download the Launcher from an external website (like Cisco’s support page) for initial setup. The installer file is actually hosted . cisco asa 5505 asdm-idm launcher download
Cisco officially ended support for the ASA 5505 on January 31, 2023. This means: If the ASA runs an old ASDM version (e
Guide to Downloading the Cisco ASDM-IDM Launcher for Go to product viewer dialog for this item. Managing your Cisco ASA 5505 6.4 or 7.2)