Cannot build image for Python FastAPI application

WARN Failed to start remote builder heartbeat: failed building options: lookup maa1.gateway.6pn.dev: no such host
Error failed to fetch an image or build from source: failed building options: lookup maa1.gateway.6pn.dev: no such host

fly.toml

app = “appname”
kill_signal = “SIGINT”
kill_timeout = 5
processes =

[build]
builder = “paketobuildpacks/builder:base”

[env]
PORT = “8080”

[experimental]
allowed_public_ports =
auto_rollback = true

[[services]]
http_checks =
internal_port = 8080
processes = [“app”]
protocol = “tcp”
script_checks =
[services.concurrency]
hard_limit = 25
soft_limit = 20
type = “connections”

[[services.ports]]
force_https = true
handlers = [“http”]
port = 80

[[services.ports]]
handlers = [“tls”, “http”]
port = 443

[[services.tcp_checks]]
grace_period = “1s”
interval = “15s”
restart_limit = 0
timeout = “2s”