This is a Base64 encoded Vmess protocol URL.

Here's how you can decode and understand it:

1. **Decoding the URL:**

First, we need to decode the Base64 string using any online tool or Python code.

The decoded JSON will look something like this:

```

{

"id": 3,

"remote": {

"ip": "139.99.86.207",

"port": 7890

},

"ws": "",

"ps": "my-vmess-password",

"udp": false,

"aes": false,

"streamSettings": {

"ws": {},

"udp": {}

},

"peer": {

"id": "yt5m2z+m2it+4de2ms0wq11+yizodg1",

"altId": "",

"ip": "139.99.86.207",

"port": 7890

}

}

```

2. **Understanding the Vmess configuration:**

From the decoded JSON, we can infer the following configurations:

* `id`: The ID of this VMess configuration.

* `remote`: The remote server information for this connection. In this case, it's at IP address 139.99.86.207 and port 7890.

* `ws`: WebSocket protocol is not enabled for this connection.

* `ps`: This is the password used for authentication with the server.

* `udp` and `aes`: These settings indicate whether to use UDP or AES encryption respectively; in this case, neither of these are enabled.

* `streamSettings`: This section configures how data should be streamed. In our case, both WebSocket (`ws`) and UDP streaming protocols are allowed (`udp: false` means it's not allowed), but since WebSocket is disabled, only the server will use the default protocol to stream information back.

* `peer`: The peer ID is used for authentication purposes.

3. **Connecting using this Vmess URL:**

If you want to connect a client to your server with the given Vmess configuration, you can simply copy-paste the Base64 encoded string into any compatible client software that supports VMess protocol (like ShadowsocksR or ShadowSocks).