FFmpeg h264_nvenc interlaced encode 1080i do not support

Hi

When i using ffmpeg process the 1080i input stream and i want to keep the stream as 1080i , I just add this command:
-flags +ilme+ildct

full ffmpeg:
ffmpeg -vsync 0 -hwaccel_device 1 -hwaccel nvdec -hwaccel_output_format cuda ‘-c:v’ ‘h264_cuvid’ ‘-deint’ ‘2’ ‘-drop_second_field’ ‘1’ -i ‘udp://239.49.17.159:4511?localaddr=127.0.0.1&timeout=10000000’ -map ‘0:v:0’ -map ‘0:a:0’ ‘-c:v’ ‘h264_nvenc’ ‘-profile:v’ ‘main’ ‘-preset:v’ ‘hp’ ‘-r’ ‘25’ -g ‘25’ -flags +ilme+ildct ‘-c:a’ ‘libfdk_aac’ ‘-ar’ ‘44100’ ‘-ac’ ‘2’ ‘-b:a’ ‘128k’ -max_muxing_queue_size 1024 ‘-b:v’ ‘1500k’ -bufsize ‘750k’ -metadata service_name=‘CCTV10’ -progress ‘udp://127.0.0.1:1510’ -flush_packets 0 -f mpegts ‘udp://239.56.33.63:8511?localaddr=127.0.0.1&pkt_size=1316’

but ffmpeg said

Input #0, mpegts, from ‘udp://239.49.17.159:4511?localaddr=127.0.0.1&timeout=10000000’:
Duration: N/A, start: 35972.938533, bitrate: N/A
Program 21
Metadata:
service_name : Zhejiang International
service_provider: Harmonic
Stream #0:0[0x214]: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(tv, smpte170m, top first), 704x480 [SAR 10:11 DAR 4:3], 29.97 fps, 59.94 tbr, 90k tbn, 59.94 tbc
Stream #0:10x314: Audio: mp2 ([4][0][0][0] / 0x0004), 48000 Hz, mono, s16p, 128 kb/s
Using -vsync 0 and -r can produce invalid output files
Stream mapping:
Stream #0:0 -> #0:0 (h264 (h264_cuvid) -> h264 (h264_nvenc))
Stream #0:1 -> #0:1 (mp2 (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
[h264_nvenc @ 0x49bf9c0] Interlaced encoding is not supported. Supported level: 0
[h264_nvenc @ 0x49bf9c0] Provided device doesn’t support required NVENC features

Error initializing output stream 0:0 – Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
[libfdk_aac @ 0x49b44c0] 2 frames left in the queue on closing

My GPU is
| NVIDIA-SMI 440.33.01 Driver Version: 440.33.01 CUDA Version: 10.2 |
|-------------------------------±---------------------±---------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
|===============================+======================+======================|
| 0 GeForce GTX 1660 Off | 00000000:01:00.0 Off | N/A |
| 47% 50C P0 29W / 120W | 1284MiB / 5944MiB | 15% Default |

Thanks