When adding chain, how to specify address family? about nftables HOT 4 CLOSED

[]byte("\x02 <----- the only difference in ipv4 case 
\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0c\x00\x03\x00\x66\x6f\x72\x77\x61\x72\x64\x00\x14\x00\x04\x80\x08\x00\x01\x00\x00\x00\x00\x02\x08\x00\x02\x00\x00\x00\x00\x00\x0b\x00\x07\x00\x66\x69\x6c\x74\x65\x72\x00\x00"),

[]byte("\x0a  <----- the only difference in ipv6 case \x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0c\x00\x03\x00\x66\x6f\x72\x77\x61\x72\x64\x00\x14\x00\x04\x80\x08\x00\x01\x00\x00\x00\x00\x02\x08\x00\x02\x00\x00\x00\x00\x00\x0b\x00\x07\x00\x66\x69\x6c\x74\x65\x72\x00\x00"),

----------------	------------------			----------------	------------------
|  0000000076  |	| message length |			|  0000000076  |	| message length |
| 02563 | R--- |	|  type | flags  |			| 02563 | R--- |	|  type | flags  |
|  0000000001  |	| sequence number|			|  0000000001  |	| sequence number|
|  0000000000  |	|     port ID    |			|  0000000000  |	|     port ID    |
----------------	------------------			----------------	------------------
| 02 00 00 00  |	|  extra header  |		      |	| 0a 00 00 00  |	|  extra header  |
|00011|--|00001|	|len |flags| type|			|00011|--|00001|	|len |flags| type|
| 66 69 6c 74  |	|      data      |	 f i l t	| 66 69 6c 74  |	|      data      |	 f i l t
| 65 72 00 00  |	|      data      |	 e r    	| 65 72 00 00  |	|      data      |	 e r    
|00012|--|00003|	|len |flags| type|			|00012|--|00003|	|len |flags| type|
| 66 6f 72 77  |	|      data      |	 f o r w	| 66 6f 72 77  |	|      data      |	 f o r w
| 61 72 64 00  |	|      data      |	 a r d  	| 61 72 64 00  |	|      data      |	 a r d  
|00020|N-|00004|	|len |flags| type|			|00020|N-|00004|	|len |flags| type|
|00008|--|00001|	|len |flags| type|			|00008|--|00001|	|len |flags| type|
| 00 00 00 02  |	|      data      |	        	| 00 00 00 02  |	|      data      |	        
|00008|--|00002|	|len |flags| type|			|00008|--|00002|	|len |flags| type|
| 00 00 00 00  |	|      data      |	        	| 00 00 00 00  |	|      data      |	        
|00011|--|00007|	|len |flags| type|			|00011|--|00007|	|len |flags| type|
| 66 69 6c 74  |	|      data      |	 f i l t	| 66 69 6c 74  |	|      data      |	 f i l t
| 65 72 00 00  |	|      data      |	 e r    	| 65 72 00 00  |	|      data      |	 e r    
----------------	------------------			----------------	------------------

table ip6 filter {
	counter fwded {
		packets 1 bytes 122
	}

	chain forward {
		type filter hook forward priority 0; policy accept;
		counter name "fwded"
		oifname "uplink0" tcp flags syn tcp option maxseg size set rt mtu
	}
}